Mārkaṇḍēya in hisPrākṛtasarvasva, i, 4, discusses the various kinds of Apabhraṁśa. In the commentary he quotes an unknown author (see Pischel,Pr. Gr., § 3, note 1) who gives a list of no less than twenty-seven, but he says that really there are only three, Nāgara, Vrācaḍa, and Upanāgara. He does not consider the others as different dialects, because their variations from the Standard are very slight.