En la vida cotidiana leemos, escuchamos, vemos un sinnúmero de estrategias destinadas a convencernos o a persuadirnos acerca de posiciones sobre los temas más diversos. Roberto Marafioti toma el tema de la argumentación, de larga tradición en Occidente, hasta llegar a sus formulaciones más actuales: Chaïm Perelman y Stephen Toulmin.
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.