1965
Buku Teks
Ritchie, Donald A., author
Macmillan, 1985
Buku Teks
Stuart, Graham H. (Graham Henry), 1887-, author
Appleton-Century-Crofts, 1955
Buku Teks
Neale, A.D., author
Cambridge University Press, 1980
Buku Teks
Jacob, Herbert, 1933-, author
Litle, Brown, 1978
Buku Teks