Chandler, Harold R.
BPC, 1970
Buku Teks
Sheffield, James R.
East African Pub. House, 1967
Buku Teks
Isaacs, Harold R.
Standford University Press, 1951
Buku Teks
Isaacs, Harold R., author
Secker & Warburg, 1938
Buku Teks
Isaacs, Harold R., author
Atheneum, 1968
Buku Teks