oleh Cleveland P. Hickman [and others]
McGraw-Hill, 2011
Buku Teks
Hickman, Cleveland P., author
McGraw-HIll, 2002
Buku Teks
Elliot, Alfred M., author
Burgess Publishing Comp., 1974
Buku Teks
Hegner, Robert W.
Macmillan, 1951
Buku Teks
Boolootin, Richard A.
Macmillan, 1981
Buku Teks