Gore, M.S., author
Asia Publishing House, 1965
Buku Teks
Cohen, Nathan Edward, author
National Ass. of Workker, 1964
Buku Teks
Ferguson, Elizabeth A., author
J.B. Lippincott, 1975
Buku Teks
Geeorge Allen , 1971
Buku Teks
Johnson, Louise C., 1923-, author
Allyn and Bacon, 1986
Buku Teks