Schelling, Thomas C., author
Yale University Press, 1966
Buku Teks
Lowry, Robert
Allen & Unwin, 1996
Buku Teks
Martin, David, author
Dove Communications, 1984
Buku Teks
Davis, Kingsley, 1908-1997, author
Macmillan, 1949
Buku Teks
Davis, Kingsley, 1908-1997, author
Macmillan, 1960
Buku Teks