Maidment, David R., editor in chief
McGraw-Hill, 1993
Buku Referensi
Brierley, Sean, 1966-, author
Routledge, 1995
Buku Referensi
edited by Martyn V. Twigg
Wolfe Publishing, 1989
Buku Referensi
Hedgecoe, John, author
Ebury, 1992
Buku Referensi
Skousen, Philip L., author
McGraw-Hill, 2011
Buku Teks