Lewis, Stephen
Oxford University Press, 1984
Buku Teks
Due, John F., author
John Hopkins Press, 1970
Buku Teks
edited by Richard M. Bird and Oliver Oldman
John Hopkins, 1967
Buku Teks
edited by David Newbery, Nicholas Stern
Oxford University Press, 1987
Buku Teks
edited by Richard M. Bird and Oliver Oldman
Johns Hopkins Press, 1964
Buku Teks