Oppenheimer, M., and L. F. Silveira. “ A Taxonomic Review of the Dark-Winged Trumpeter Psophia Viridis (Aves: Gruiformes: Psophiidae) ”. Papéis Avulsos De Zoologia, vol. 49, no. 41, Jan. 2009, pp. 547-55, doi:10.1590/S0031-10492009004100001.