References used in the Egg webpages

Barrows, W.B. Michigan Bird Life. Michigan Agriculture College, 1912

Drent R., 1975. Incubation. Pp. 333-420 in Avian Biology, Vol. 5 (D. S. Farner and J. R. King, Eds.). New York, Academic Press.

Hickey, J.J. and D.W. Anderson. 1968. Chlorinated hydrocarbons and eggshell changes in raptorial and fish-eating birds. Science, 162:271-273.

Richter, Carl H. 1937. Bonaparte's Gull nesting in Wisconsin; a record. Oologist 54(1): 5-7.

Robbins, Samuel D. 1991. Wisconsin Birdlife: population and distribution past and present. 720 pp.

Van Winkle, E. The American Herring Gull. Bull. Mich. Orn. Club, I, 1897, p 33.

Van Winkle, E. The Caspian or Imperial Tern. Oologist, X, 1893, p 114.