Hall, R.P.
Blaisdell Publishing, 1964
Buku Teks
Whitney, Ellie
Wadsworth and Cengage Learning, 2013
Buku Teks
Wardlaw, Gordon M., 1912-1989
McGraw-Hill, 2004
Buku Teks
Damanik, Indra Rukmana
Fakultas Kesehatan Masyarakat Universitas Indonesia, 2012
UI - Skripsi (Open)
Fleck, Henrietta
Macmillan, 1966
Buku Teks