The first major descriptive study of linguistics vagueness - arguably the strategies of which constitute a key aspect of communicative competence of native speakers of English. This study shows how English provides its speakers with a great variety of ways of being vague and draws on naturally-occurring data to examine syntactic, intonational, semantic, and pragmatic considerations of vague language.
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.
Fascinating early look at the role vague language plays in English discourse. I'd be curious to read a more recent analysis, as the corpora of spoken English must be larger now than they were 30 years ago. Also, while this is certainly not hardcore linguistics, those with a more casual interest in the topic may find it a bit too technical.