Barnet, Sylvan, author
Little, Brown, 1979
Buku Teks
Mahmoud, Shah, author
Betterway, 1992
Buku Referensi
O`Shea, Robert P. (Robert Paul), 1953-, author
Harcourt Brace & Company, 1996
Buku Teks
O`Shea, Robert P. (Robert Paul), 1953-, author
Harcourt Brace Jovanovich, 1993
Buku Teks
Sklare, Arnold B., author
McGraw-Hill, 1964
Buku Teks