Denhardt, Robert B., author
Thomson/Wadsworth, 2004
Buku Teks
Denhardt, Robert B., author
Cengage Learning, 2015
Buku Teks
Rainey, Hal G., author
Jossey-Bass, 2014
Buku Teks
Self, Peter, author
George Allen & Unwin, 1974
Buku Teks
Grolier, Eric de, author
Unesco, 1979
Buku Teks