Scheffran, Jurgen, editor
Springer, 2012
eBooks
Huxley, Aldous
New York, Harper & Brothers, 1956
Buku Teks
Jolly, D., author
World Health Organization, 1992
Buku Teks
Drucker, Peter F. (Peter Ferdinand), 1909-2005, author
Harper & Brothers, 1959
Buku Teks
Ferriss, Hugh, author
Dover Publications, 2005
Buku Teks