Gates, Jean Key, author
McGraw-Hill, 1994
Buku Referensi
Gates, Jean Key, author
McGraw-Hill, 1974
Buku Referensi
Wild, John J., author
Irwin/McGraw-Hill, 2000
Buku Teks
Parker, C.C. (Christopher Charles), author
Butterworths, 1960
Buku Teks
Thompson, Anthony, author
UNESCO, 1983
Buku Referensi