Olson, S. L., and H. Matsuoka. “New Specimens of the Early Eocene Frigatebird Limnofregata (Pelecaniformes: Fregatidae), With the Description of a New Species”. Zootaxa, vol. 1046, no. 1, Sept. 2005, pp. 1–15, doi:10.11646/zootaxa.1046.1.1.