Theodore Roosevelt

Protective coloration

African Game Trails, Syndacate Publishing Company, New York 1910, pp. 552-568.

Theodore Roosevelt

Revealing and concealing coloration in birds and mammals

Bulletin of the American Museum of Natural History, Vol. 30, American Museum of Natural History, New York 1911, pp. 119-231.

Abbott Handerson Thayer

Concealing coloration

Popular Science Monthly, Vol. 79, The Science Press, New York giugno 1911, pp. 20-35.