Hart, James D., author
Oxford University Press, 1986
Buku Referensi
United State Information Agency, 1994
Buku Teks
Hart, James, author
Oxford University Press, 1965
Buku Referensi
edited by Robert Richards
Littlefield, Adams, 1955
Buku Referensi
Houghton Miffiln, 1958
Buku Teks