^"Progenitohyus". The Paleobiology Database. Retrieved 13 June 2024.
^Ducrocq, Stéphane (2019). "Pakkokuhyus and Progenitohyus (Artiodactyla, Mammalia) from the Eocene of Southeast Asia are not Helohyidae: paleobiogeographical implications". PalZ. 93 (1): 105–113. Bibcode:2019PalZ...93..105D. doi:10.1007/s12542-018-0425-5.