Columbia subject headings:
English language--Dictionaries.
English language--Synonyms and antonyms--Dictionaries.
Synonyms.
Thesauri.
Harvard subject headings:
English language--Synonyms and antonyms--Dictionaries.
Princeton subject headings:
Dictionaries.
English language--Dictionaries.
English language--Synonyms and antonyms.
Synonyms.
Thesauri.