Greenwood, Ted, 1944-, author
Ballinger, 1975
Buku Teks
Hitch, Charles J., author
University of California Press, 1965
Buku Teks
Van de Ven, Andrew H., author
Kent State University Press, 1974
Buku Teks
edited by Hermann Brandstatter
Academic Press, 1982
Buku Teks
Raven press, 1983
Buku Teks