Penna, Anthony N, author
Blackwell, 2013
Buku Teks
Allaby, Michael, author
Macmillan, 1985
Buku Referensi
Allaby, Michael, author
Macmillan, 1991
Buku Referensi
edited by W.F. Bynum, E.J. Browne, Roy Porter
Macmillan Reference Books, 1989
Buku Referensi
Gary G. Bitter, editor in chief
Macmillan, 1992
Buku Referensi