Various authors

The expression "various authors" is used to credit creative works which are the result of a collaboration. In English it is more common to describe the authors of such a compilation collectively, for example by saying for what occasion the texts were written or by naming one writer, for example the first one in the alphabet, and then adding et [al.]
It may be abbreviated as Vv.Aa., which is rarely used in English except by non-native speakers, who look for an exact equivalent to similar terms in Italian, Spanish, and some other languages. The expansion of the acronym is the Latin expression auctores varii.