diff --git a/src/hash.h b/src/hash.h
deleted file mode 100644
index 24d142c..0000000
--- a/src/hash.h
+++ /dev/null
@@ -1,9 +0,0 @@
-#include <stdint.h>
-
-/** djb2 <http://www.cse.yorku.ca/~oz/hash.html> */
-static uint32_t djb2(const char *s) {
-	const unsigned char *str = (const unsigned char *)s;
-	uint32_t hash = 5381, c;
-	while(c = *str++) hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
-	return hash;
-}
diff --git a/src/helper.h b/src/helper.h
deleted file mode 100644
index 7494073..0000000
--- a/src/helper.h
+++ /dev/null
@@ -1,29 +0,0 @@
-#include <stdint.h>
-#include <errno.h>
-
-/** Parse unsigned; [`s`,`e`) => `n`. */
-static int helper_natural(const char *s, const char *const e, uint32_t *const n)
-{
-	uint32_t accum = 0;
-	while(s < e) {
-		unsigned next = accum * 10 + (unsigned)(*s - '0');
-		if(accum >= next) return errno = ERANGE, 0;
-		accum = next;
-		s++;
-	}
-	*n = accum;
-	return 1;
-}
-
-/** djb2 <http://www.cse.yorku.ca/~oz/hash.html> */
-static uint32_t djb2(const char *s) {
-	const unsigned char *str = (const unsigned char *)s;
-	uint32_t hash = 5381, c;
-	while(c = *str++) hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
-	return hash;
-}
-
-static void unused_helper_coda(void);
-static void unused_helper(void)
-	{ helper_natural(0, 0, 0); djb2(0); unused_helper_coda(); }
-static void unused_helper_coda(void) { unused_helper(); }
diff --git a/src/pair.c b/src/pair.c
index 886f88e..b1df775 100644
--- a/src/pair.c
+++ b/src/pair.c
@@ -1,6 +1,7 @@
 #include "pair.h"
 #include <stdint.h>
 #include <errno.h>
+#include <assert.h>
 
 /** @return Constructs `a` and `b` as a pair. */
 struct pair pair(const char *const a, const char *const b) {
@@ -22,3 +23,21 @@ int pair_to_natural(const char *s, const char *const e, uint32_t *const n) {
 	*n = accum;
 	return 1;
 }
+
+int pair_is_equal(struct pair x, struct pair y) {
+	assert(x.a <= x.b && y.a <= y.b);
+	if(!x.a) return !y.a;
+	if(x.b - x.a != y.b - y.a) return 0;
+	while(x.a < x.b) { if(*x.a != *y.a) return 0; x.a++, y.a++; }
+	return 1;
+}
+
+/** djb2 <http://www.cse.yorku.ca/~oz/hash.html> */
+uint32_t pair_djb2(struct pair p) {
+	uint32_t hash = 5381, c;
+	while(p.a < p.b) {
+		c = (unsigned char)*p.a++;
+		hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
+	}
+	return hash;
+}
diff --git a/src/pair.h b/src/pair.h
index 0b3d66a..f010a65 100644
--- a/src/pair.h
+++ b/src/pair.h
@@ -3,3 +3,5 @@
 struct pair { const char *a, *b; };
 struct pair pair(const char *const a, const char *const b);
 int pair_to_natural(const char *, const char *, uint32_t *);
+int pair_is_equal(struct pair, struct pair);
+uint32_t pair_djb2(const struct pair p);
diff --git a/src/source.h b/src/source.h
index f7f6486..3219e1c 100644
--- a/src/source.h
+++ b/src/source.h
@@ -1,12 +1,13 @@
 #if defined BASE \
 	|| !defined BASE && !defined GENERIC && !defined PROTO /* <!-- base */
-//#include "lorem.h"
-/*void kjvcite_to_string(const union kjvcite, char (*)[12]);*/
+#include "pair.h"
+struct source { struct pair name, desc; };
 #endif /* base --> */
 
 
 #if defined GENERIC \
 	|| !defined BASE && !defined GENERIC && !defined PROTO /* <!-- generic */
+
 struct tree_source_node;
 struct tree_source_tree { struct tree_source_node *node; unsigned height; };
 struct source_tree { struct tree_source_tree root; };
@@ -15,13 +16,26 @@ struct tree_source_iterator {
 	struct tree_source_tree *root; struct tree_source_ref ref; int seen;
 };
 struct source_tree_iterator { struct tree_source_iterator _; };
+
+struct sourcelist_array { struct source *data; size_t size, capacity; };
+
+struct sourcelook_bucket;
+struct sourcelook_table {
+	struct sourcelook_bucket *buckets;
+	uint32_t log_capacity, size, top;
+};
+
 #endif /* generic --> */
 
 
 #if defined PROTO \
 	|| !defined BASE && !defined GENERIC && !defined PROTO /* <!-- proto */
 #include <stddef.h>
-struct sources { struct source_tree _; };
+struct sources {
+	struct sourcelist_array list;
+	struct sourcelook_table look;
+	struct source_tree dates;
+};
 struct source *sources_add(struct sources *, const union line64);
 struct sources sources(struct journal *);
 void sources_(struct sources *);
diff --git a/src/source.re.c b/src/source.re.c
index e37241b..91609df 100644
--- a/src/source.re.c
+++ b/src/source.re.c
@@ -4,39 +4,44 @@
 #define BASE
 #include "../src/source.h" /* base */
 #include "../src/journal.h"
-#include "../src/hash.h" /* djb2 */
-#include "../src/pair.h"
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 #include <assert.h>
 
-/* fixme: ...wait, why would you copy? modify the table to use substring. */
 
-/* This is a lookup table for source strings ("2000glider") to substring the
- first description ("Glider pilot log book"). */
-static int lookup_is_equal(const char *const x, const char *const y)
-	{ return !strcmp(x, y); }
-static uint32_t lookup_hash(const char *const x) { return djb2(x); }
-static void lookup_to_string(const char *x, const struct pair desc,
-	char (*const a)[12]) { (void)desc; sprintf(*a, "%.11s", x); }
-static struct pair lookup_default = { 0, 0 };
-#define TABLE_NAME lookup
-#define TABLE_KEY char *
+static void sourcelist_to_string(const struct source *const s,
+	char (*const z)[12]) {
+	const char *a = s->name.a, *b;
+	char *y = *z;
+	b = s->name.b <= a + 11 ? s->name.b : a + 11;
+	while(a < b) *(y++) = *(a++);
+	*y = '\0';
+}
+#define ARRAY_NAME sourcelist
+#define ARRAY_TYPE struct source
+#define ARRAY_TO_STRING
+#include "../src/array.h"
+
+
+static int sourcelook_is_equal(const struct pair a, const struct pair b)
+	{ return pair_is_equal(a, b); }
+static uint32_t sourcelook_hash(const struct pair p) { return pair_djb2(p); }
+#define TABLE_NAME sourcelook
+#define TABLE_KEY struct pair
 #define TABLE_UINT uint32_t
-#define TABLE_VALUE struct pair
-#define TABLE_DEFAULT lookup_default
-#define TABLE_TO_STRING
+#define TABLE_VALUE size_t /* Index into `lookup_sources`. */
+#define TABLE_DEFAULT 0
 #include "../src/table.h"
 
 
-static void source_to_string(const union line64 line, char *const*const u,
+static void source_to_string(const union line64 line, const size_t *const u,
 	char (*const a)[12]) { (void)u; date32_to_string(line.date, a); }
 static int source_compare(const union line64 a, const union line64 b)
 	{ return a.u64 > b.u64; }
 #define TREE_NAME source
 #define TREE_KEY union line64
-#define TREE_VALUE char *
+#define TREE_VALUE size_t /* Index into `lookup_sources`. */
 #define TREE_COMPARE
 #define TREE_TO_STRING
 #include "../src/tree.h"
@@ -81,16 +86,32 @@ static int scan(union date32 date, const char *const buffer,
 		<line> "--" / [^-] :=> source
 
 		<source> * { why = "default source unrecognized"; goto catch; }
-		<source> @s0 keyword @s1 / "\n" => skip {
+		<source> @s0 keyword @s1 / "\n" => skip { also_add_to_tree: {
 			struct pair p = pair(s0, s1);
-			const char *label;
+			size_t i;
+			if(!(i = sourcelook_table_get(&s->look, p)))
+				{ why = "keyword not introduced"; goto catch; }
 			printf("extracted <%.*s>\n", (int)(s1 - s0), s0);
 			continue;
-		}
+		} }
 		/* This is lazy and will pickup trailing spaces. */
 		<source> @s0 keyword @s1 ":" [^\x00\n]+ / "\n" => skip {
-			printf("new keyword <%.*s>\n", (int)(s1 - s0), s0);
-			continue;
+			struct pair keyword = pair(s0, s1);
+			size_t *idx;
+			struct source *source;
+			switch(sourcelook_table_assign(&s->look, keyword, &idx)) {
+			case TABLE_PRESENT: errno = EDOM; why = "new keyword already used";
+			case TABLE_ERROR: goto catch; /* /\ _Sic_. */
+			case TABLE_ABSENT: break; /* Good. */
+			}
+			*idx = 0; /* Clean. */
+			if(!(source = sourcelist_array_new(&s->list))) goto catch;
+			*idx = (size_t)(source - s->list.data);
+			source->name.a = s0, source->name.b = s1;
+			source->desc.a = 0, source->desc.b = 0;
+			fprintf(stderr, "New keyword <%.*s> stored in list at %zu.\n",
+				(int)(s1 - s0), s0, *idx);
+			goto also_add_to_tree;
 		}
 	*/ }
 	assert(0); /* Never gets here. */
@@ -105,22 +126,29 @@ catch:
  be false. */
 void sources_(struct sources *const s) {
 	if(!s) return;
-	source_tree_(&s->_);
+	source_tree_(&s->dates);
+	sourcelook_table_(&s->look);
+	sourcelist_array_(&s->list);
 }
 
 struct sources sources(struct journal *const j) {
-	struct sources s;
+	struct sources s
+		= { sourcelist_array(), sourcelook_table(), source_tree() };
 	struct journal_iterator it;
 	union date32 k;
 	const char *v;
 	assert(j);
-	s._ = source_tree();
+	{ /* Null is the first item for convenience, (TABLE_DEFAULT). */
+		struct source *nul;
+		if(!(nul = sourcelist_array_new(&s.list))) goto catch;
+		nul->name.a = nul->name.b = nul->desc.a = nul->desc.b = 0;
+	}
 	it = journal_begin(j);
 	while(journal_next(&it, &k, &v)) if(!scan(k, v, &s)) goto catch;
+	printf("%s\n", sourcelist_array_to_string(&s.list));
 	goto finally;
 catch:
 	sources_(&s);
 finally:
-	//char_array_(&temp); /* Erase the temporary buffer. */
 	return s;
 }
diff --git a/src/table.h b/src/table.h
index 0f1416d..cebd773 100644
--- a/src/table.h
+++ b/src/table.h
@@ -626,7 +626,7 @@ static void N_(table_clear)(struct N_(table) *const table) {
 }
 
 /** @return Whether `key` is in `table` (which can be null.) @allow */
-static int N_(table_is)(struct N_(table) *const table, const PN_(key) key) {
+static int N_(table_contains)(struct N_(table) *const table, const PN_(key) key) {
 	/* This function must be defined by the user. */
 	return table && table->buckets
 		? !!PN_(query)(table, key, N_(hash)(key)) : 0;
@@ -635,7 +635,7 @@ static int N_(table_is)(struct N_(table) *const table, const PN_(key) key) {
 #ifdef TABLE_VALUE /* <!-- map */
 /** If the entire entry space is filled, use this. Otherwise, a more convenient
  function is <fn:<N>table_get_or>.
- @param[result] If null, behaves like <fn:<N>table_is>, otherwise, a
+ @param[result] If null, behaves like <fn:<N>table_contains>, otherwise, a
  <typedef:<PN>key> which gets filled on true.
  @param[value] Only on a map with `TABLE_VALUE`. If not-null, stores the value.
  @return Whether `key` is in `table` (which can be null.) @allow */
@@ -794,7 +794,7 @@ static void PN_(unused_base)(void) {
 	PN_(entry) e; PN_(key) k; PN_(value) v;
 	memset(&e, 0, sizeof e); memset(&k, 0, sizeof k); memset(&v, 0, sizeof v);
 	N_(table)(); N_(table_)(0); N_(table_begin)(0);
-	N_(table_buffer)(0, 0); N_(table_clear)(0); N_(table_is)(0, k);
+	N_(table_buffer)(0, 0); N_(table_clear)(0); N_(table_contains)(0, k);
 	N_(table_get_or)(0, k, v);
 	N_(table_update)(0, k, 0); N_(table_policy)(0, k, 0, 0);
 	N_(table_remove)(0, k); N_(table_iterator_remove)(0);
diff --git a/test/test_journal.c b/test/test_journal.c
index b2110e7..3ec8108 100644
--- a/test/test_journal.c
+++ b/test/test_journal.c
@@ -15,7 +15,7 @@ int main(void) {
 		const char *value;
 		if(!(journal_next(&it, &date, &value))) goto catch;
 		printf("%u-%u-%u\n"
-			"<%s>", date.year, date.month, date.day, value);
+			"<%s>\n", date.year, date.month, date.day, value);
 	}
 	goto finally;
 catch: