Howard, Bion B.
McGraw-Hill Book Company, Inc., 1953
Buku Teks
Prima Yunita Diyan Ruswati
Fakultas Kesehatan Masyarakat Universitas Indonesia, 2009
UI - Tesis (Open)
Green, Charles H.
McGraw-Hill , 2012
Buku Teks
Joy, O. Maurice
Richard D. Irwin. Inc., 1980
Buku Teks
Prentice-Hall, 1993
Buku Teks