Artikel Jurnal
Indonesia. Ministry of Health. Bureau of Education and Tranning
Departemen Kesehatan, 1973
Buku Teks
Burrows, Toby, author
The Howorth, 1989
Buku Teks
Gelfand, M.A., author
Unesco, 1971
Buku Teks
edited by D.J. Evans
Academic Press, 19974
Buku Teks