Novas, Fernando E.; Puertat, Pablo F. New Evidence Concerning Avian Origins from the Late Cretaceous of Patagonia. Nature. 1997, 387 (6631): 390−392. Bibcode:1997Natur.387..390N. doi:10.1038/387390a0.
Novas, Fernando E.; Puertat, Pablo F. New Evidence Concerning Avian Origins from the Late Cretaceous of Patagonia. Nature. 1997, 387 (6631): 390−392. Bibcode:1997Natur.387..390N. doi:10.1038/387390a0.