Stephen Johnston... [et al.]
Harper Educational, 1995
Buku Teks
Foster, Lois E., author
Prentice-Hall, 1981
Buku Teks
Edgar, Donald Ernest
Prentice-Hall, 1980
Buku Teks
Parkin, Andrew
Macmillan, 1982
Buku Teks
Hicks, Philip E., author
McGraw-Hill, 1998
Buku Teks