United Nations Development Programme, 1980
Buku Teks
I Gde Suyatna
Universitas Indonesia, 1982
Buku Teks
Carlson, John E., author
McGraw-Hill, 1981
Buku Teks
C. Pramuwito, author
B2P3KS, 1998
Buku Teks
Kurtz, Marcus J., author
Cambridge University Press, 2004
Buku Teks