Oral gospel traditions called the M source for Matthew and the L source for Luke, which may have been a mix of written and oral material (see Two-source hypothesis). Most scholars believe that the author of John's gospel used oral and written sources different from those available to the Synoptic authors – a "signs" source, a "revelatory discourse" source, and others – although there are indications that a later editor of this gospel may have used Mark and Luke. Oral transmission may also be seen as a different approach to understanding the Synoptic Gospels in New Testament scholarship. Current theories attempt to link
New Testament apocrypha and produce new translations. The texts of the Nag Hammadi library are often considered separately but the current edition of Schneemelcher also contains eleven Nag Hammadi texts. Books that are known objectively not to have existed in antiquity are usually not considered part of the New Testament Apocrypha. Among these are the Libellus de Nativitate Sanctae Mariae (also called the "Nativity of Mary") and the Latin Infancy gospel. The latter two did not exist in antiquity, and they seem to be based on the earlier Infancy gospels. Four gospels came to be accepted as part of the New Testament canon.