Brewer, Richard, author
Saunders College Publishing, 1982
Buku Teks
Meiners, Harry F.
John Wiley & Sons, 1969
Buku Teks
Brewer, Richard, author
Saunders College Publishing, 1982
Buku Referensi
Fischbach, Frances Talaska, author
Lippincot Company, 1992
Buku Teks
Cox, George W., author
Wm. C. Brown, 1996
Buku Teks