ISLER, M. L.; ISLER, P. R.; WHITNEY, B. M.; ZIMMER, K. J.; WHITTAKER, A. Species limits in antbirds (Aves: Passeriformes: Thamnophilidae): an evaluation of Frederickena unduligera (Undulated Antshrike) based on vocalizations. Zootaxa, Auckland, New Zealand, v. 2305, n. 1, p. 61–68, 2009. DOI: 10.11646/zootaxa.2305.1.5. Disponível em: https://mapress.com/zt/article/view/zootaxa.2305.1.5. Acesso em: 11 apr. 2025.