Spadaccini, Michael, author
Ep Entrepreneuir Press, 2011
Buku Teks
Wegmann, T., author
Editiones Roche, 1987
Buku Teks
Richards, Ann, author
Elsevier, 208
Buku Teks
Hutauruk, Susi Mariana, author
Fakultas Kesehatan Masyarakat Universitas Indonesia, 2007
UI - Tesis (Membership)
Wilson, Billie Ann, author
Prentice-Hall, 2003
Buku Referensi