Lansing, John B.
University of Michigan, 1971
Buku Teks
Directorate of Secondary Education, 1998
Buku Teks
BUTKSI, 1973
Buku Teks
Moser, Claus A., author
Heineman Education Books, 1979
Buku Teks
World Health Organization
World Health Organization, 2013
Buku Teks