Kicthen, Ronald
Oxford : Newnes, 2003
Buku Referensi
Ari Dwi Jayanti
Universitas Indonesia, 2014
UI - Skripsi Membership
World Health Organization, 2000
Buku Teks
edited by Jamie V. Trapp and Tomas Kron
Taylor & Francis Group, 2008
Buku Teks
Frankel, Robert
John Wiley & Sons, 1976
Buku Teks SO