1938. Life histories of North American birds of prey (Part 2), Orders Falconiformes and Strigiformes. U. S. Nat. Mus., Bull. 170, viii + 482 pp.
Fitch, H. S., Swenson, F., and Tillotson, D. F.
1946. Behavior and food habits of the Red-tailed Hawk. Condor, 48:205-237.
Huggins, S. E.
1940. Relative growth in the House Wren. Growth, 4:225-236.
Riddle, O., Charles, D. R., and Cauthen, G. E.
1932. Relative growth rates in large and small races of pigeons. Proc. Soc. Exp. Biol. and Med., 29:1216-1220.
Stoner, D.
1935. Temperature and growth studies on the Barn Swallow. Auk, 52:400-407.
1945. Temperature and growth studies of the Northern Cliff Swallow. Auk, 62:207-216.