Lewis, M. K. (Mervyn Keith), author
Philip Allan , 1987
Buku Teks
Hopper, Melvyn A., author
Eurasia Media, 1985.
Buku Teks
Halm, George N., author
Richard D. Irwin, 1956
Buku Teks
edited by Allen N. Berger, Philip Molyneux and John O.S. Wilson
Oxford University Press, 2015
Buku Referensi
Holden, J. Milnes, author
Sir Isaac Pitman & Sons, 1960
Buku Teks