Hartman, William K., author
Wadswoth, 1978
Buku Teks
Moche, Dinah L., author
John Wiley & Sons, 1981
Buku Teks
Huffer, Charles M.
Holt Rinehart & Winston, 1967
Buku Teks
Wood, Harley
Angus and Robertson, 1967
Buku Teks
Morrison, David, author
Saunders College, 1990
Buku Teks