The Concise Oxford Thesaurus provides coverage of over 300,000 synonyms and antonyms, making it the ideal reference tool to improve your writing style or find the word you need to solve that crossword or puzzle. Published 2007-06-19
Various is the correct author for any book with multiple unknown authors, and is acceptable for books with multiple known authors, especially if not all are known or the list is very long (over 50).
If an editor is known, however, Various is not necessary. List the name of the editor as the primary author (with role "editor"). Contributing authors' names follow it.
Note: WorldCat is an excellent resource for finding author information and contents of anthologies.