Li, David H.
Charles E. Merrill, 1966
Buku Teks
Hansen, Don R.
South-Western College, 2000
Buku Teks
Hansen, Don R.
South-Western College Publishing, 1997
Buku Teks
Hansen, Don R.
South-Western College Publishing, 1997
Buku Teks
Killough, Larry N.
Dickenson Publishing, 1977
Buku Teks