scientific article published in 1950

scientific article published on 24 April 2006

scientific article published on 9 September 1939

scientific article published in 1939

scientific article published in 1938

scientific article published in 1927

Chicago: The University of Chicago Press, 1931.

Baltimore, The Williams & Wilkins Company and Associates in cooperation with the Century of Progress Exposition, 1932.

scientific article published in 1934

scientific article published in 1954

scientific article published in 1930

scientific article published on 18 August 1937

scientific article published on 2 June 1952

scientific article published in 1937

scientific article published in 1937

scientific article published in 1938

scientific article published in 1930

scientific article published in 1935

scientific article published on 03 May 2006

Chicago, Rand McNally & Company[c1925]

scientific article published in 1942

Philadelphia, Saunders Co., 1949.

article

scientific article published on 9 September 1939

article by A. M. Guhl and W. C. Allee, publ. July, 1944

scientific article published in 1923

scientific article published in 1932

scientific article published in 1914

written work by W. C. Allee