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.
Es la primera vez que leo una recopilación de Medellín en 100 palabras, y quedé en shock, de una buena forma, pero con el sinsabor de que la ciudad de la eterna primavera oculta una ciudad carcomida por el dolor y la ausencia, la guerra y el quizás.