Hazel, John, author
Routledge, 2000
Buku Teks
Hazel, John, author
Routledge, 2000
Buku Referensi
editor, John R. Hinnells
Macmillan, 1993
Buku Referensi
edited by John Keegan
Routledge, 1995
Buku Teks
edited by Daniel Meyer-Dingrafe
Routledge, 2000
Buku Referensi