Godwin, C. J.
Tata McGraw-Hill, 1972
Buku Teks
edited by George Dalton
New York, 1971
Buku Teks
Ponsioen, J.A.
Mouton, 1969
Buku Teks
Moore, Wilbert E. (Wilbert Ellis), author
Prentice-Hall, 1963
Buku Teks
edited by Robert A. Nisbet
Blackwell, 1972
Buku Teks