Johnson, Kevin P. & Sorenson, Michael D. (1999): "Phylogeny and biogeography of dabbling ducks (genus Anas): a comparison of molecular and morphological evidence." Auk116(3): 792?805. PDF fulltext (texto completo)Arquivado 05 de febreiro de 2007 en Wayback Machine.
Livezey, Brad C. (1986): A phylogenetic analysis of recent anseriform xera using morphological characters. Auk, 103(4): 737-754. PDF fulltextArquivado 05 de agosto de 2010 en Wayback Machine.
Livezey, Brad C. (1998): A phylogenetic analysis of modern pochards (Anatidae: Aythyini). Auk, 113(1): 74?93. PDF fulltextArquivado 04 de xuño de 2010 en Wayback Machine.
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Johnson, Kevin P. & Sorenson, Michael D. (1999): "Phylogeny and biogeography of dabbling ducks (genus Anas): a comparison of molecular and morphological evidence." Auk116(3): 792?805. PDF fulltext (texto completo)Arquivado 05 de febreiro de 2007 en Wayback Machine.
Livezey, Brad C. (1986): A phylogenetic analysis of recent anseriform xera using morphological characters. Auk, 103(4): 737-754. PDF fulltextArquivado 05 de agosto de 2010 en Wayback Machine.
Livezey, Brad C. (1998): A phylogenetic analysis of modern pochards (Anatidae: Aythyini). Auk, 113(1): 74?93. PDF fulltextArquivado 04 de xuño de 2010 en Wayback Machine.