Pelz, Ruth.
Murray Pub. Co, 1979
Buku Teks
Johnson, Miranda, author
Oxford University Press, 2016
eBooks
Published for Newsweek by Funk & Wagnalls, 1950
Buku Teks
Adrian, Charles R., author
McGraw-Hill , 1978
Buku Teks
Eagleton, Clyde
New York University press, 1945
Buku Teks