National Academy of Science, 1974
Buku Teks
Spengler, Joseph J. (Joseph John), 1902-1991, author
Prentice-Hall, 1974
Buku Teks
Tan, Ngoc Chau
Unesco, 1972
Buku Teks
edited by Stanley Johnson
John Wiley & Sons, 1973
Buku Teks
Wrong, Dennis H
Random House, 1985
Buku Teks