Havelock, Ronald G., author
Praeger Publ., 1978
Buku Teks
edited by David Newbery, Nicholas Stern
Oxford University Press, 1987
Buku Teks
edited by Robert F. Arnove
Preager, 1976
Buku Teks
edited by Sunil Mani, Henny Romijn
United Nations University Press, 2004
Buku Teks
Riggs, Fred W., author
Houghton Miffiln, 1964
Buku Teks