Brewer, Derek
Longman, 1984
Buku Teks
edited by Richard J. Schoeck and Jerome Taylorand
University of Notre Dame Press, 1968
Buku Teks
Rudd, Gillian, author
Routledge , 2001
Buku Teks
Fichte, Joerg O.
Guntur Narr Verlag, 1980
Buku Teks
Ward, Adolphus William, author
Macmillan, 1879
Buku Teks