edited by Werner Sichel
Ann Arbor, 1970
Buku Teks
Bauer, P.T., author
Frederick A. Praeger, 1961
Buku Teks
Macgregor, D.H., author
Oxford University Press, 1949
Buku Teks
Tinbergen, Jan, 1903-, author
North-Holland Publishing , 1952
Buku Teks
Walker, E. Ronald, author
University of Chicago Press, 1947
Buku Teks