McCullagh, C. Behan
Routledge, 1998
Buku Teks
Marmysz, John, 1964-
Wadsworth and Cengage Learning, 2012
Buku Teks
Blundell, Nigel
Octopus Books Limited, 1980
Buku Teks
Dunham, Barrows
Little, Brown and Company, 1947
Buku Teks
Dunham, Barrows
Little, Brown and Company, 1947
Buku Teks