Brown, L. and D. Amadon, 1968. Eagles, hawks, and falcons of the world. McGraw-Hill Book Co. pp. 562-563
Dingus, L. and T. Rowe, 1998. The mistaken extinction; dinosaur evolution and the origin of birds. W.H. Freeman and Co., New York. pp. 229-244.
Hackett, S., R. Kimball, S. Redy, R. Bowie, E. Braun, M. Braun, J. Chojnowski, W. Cox, K. Han, J. Harshman, C. Huddleston, B. Marks, K. Miglia, W. Moore, F. Sheldon, D. Steadman, C. Witt, T. Yuri, 2008. A phylogenetic study of birds reveals their evolutionary history. Science 320(5884):1763-1767
Miller, L. 1915. A walking eagle from Rancho La Brea. Condor 17(5):179-181.
Miller, L. 1928. Generic re-assignment of Morphnus daggetti. Condor. 30:255-256
Olson, Storrs 2007. The "Walking Eagle" Wetmoregyps daggetti Miller: a scaled-up version of the Savanna Hawk (Buteogallus meridionalis). Ornithological monographs 63(1):110-114.
Steadman, D. and P. Martin 1984. Extinction of birds in the Late Pleistocene of North America. P. Martin and R. Klein (Eds.) In: Quaternary extinctions: a prehistoric revolution. University of Arizona Press, Tucson, Arizona. pp. 466-477.
Stedman, D., J. Arroyo-Cabrales, E. Johnson, A. Guzman, 1994. New information on the Late Pleistocene birds from San Josecito Cave, Nuevo León, Mexico. Condor 96(3):577-586.