Doris, Lillian
Prentice-Hall, 1960
Buku Teks
Bredow, Miriam
McGraw-Hill, 1964
Buku Teks
Dixit, J.N. (Jyotindra Nath), 1936-2005.
UBS Publishers' Distributors, 1996.
Buku Teks
Roherty, James M.
University of Miami Press, 1970
Buku Teks
New York United Nations 1964,
Buku Teks