Asfahl, C. Ray
Pearson/Prentice Hall, 2004
Buku Teks SO
Reese, Charles D.
CRC Press, Taylor and Francis Group, 2009
Buku Teks
Donny Adam
Universitas Indonesia, 2008
UI - Tesis Open
CCH Australia , 2001
Buku Teks
Simorangkir, Linchon Hasiholan.
Fakultas Kesehatan Masyarakat Universitas Indonesia, 2014
UI - Skripsi Membership