Thayer, Nathaniel B.
Princeton University Press, 1973
Buku Teks
Suckling, Colin J.
Universal Book Stall, 1995
Buku Teks
Roll, Charles W.
Seven Locks Press, 1980
Buku Teks
Wasserman, Max J.
D.C. Health and Company, 1966
Buku Teks
Curry, Dudley W.
Prentice- Hall International , 1972
Buku Teks