World Health Organization
World Health Organization, 1998
Buku Teks
edited by Bryant W. Rossiter
John Wiley & Sons, 1980
Buku Teks
Huckabay, Loucine M. Daderian, author
Mosby Comp., 1980
Buku Teks
Gagne, Robert M.
Holt, Rinehart and Winston, 1970
Buku Teks
Solikin M. Juhro, author
Bank Indonesia Insitute , 2019
Artikel Jurnal