Spear, Percival, author
The University of Michigan Press, 1961
Buku Teks
Blair, John M., author
Johnson Reprint Corporation, 1972
Buku Teks
Paragon International Publishers, 2006
Buku Teks
Arora, Satish K., author
Holt, Rinchart and Winston , 1969
Buku Teks
Nguyen-Truong
Regional Institute of Higher Education and Development , 1974
Buku Teks