Page, Malcolm, author
Macmillan Education, 1987
Buku Teks
edited by Nicholas Brooke
Macmillan, 1978
Buku Teks
Knopp, Werner
Inter Nationes, 1986
Buku Teks
Ely, Vivien King
Gregg Division, McGraw-Hill, 1990
Buku Teks
Stillman II, Richard, author
Thomson, 2004
Buku Teks