Rando, J., Pieper, H., Olson, S. L., Pereira, F., & Alcover, J. (2017).

A new extinct species of large bullfinch (Aves: Fringillidae: Pyrrhula) from Graciosa Island (Azores, North Atlantic Ocean)

. Zootaxa, 4282(3), 567–583. https://doi.org/10.11646/zootaxa.4282.3.9