Ewing, J.H., editor
Dell Publishing, 1964
Buku Teks SO
edited by Stewart Sutherland, Leslie Houlden, Peter Clarke, Friedhelm Hardy
Routledge, 1988
Buku Referensi
Ferm, Vergillius
Littlefield, Adams, 1961
Buku Teks SO
Hutchinson, 1959
Buku Referensi
Dirks, Jerald F., author
Almahira, 2006
Buku Teks