Klenk, Robert W.
Wadsworth, 1974
Buku Teks
Klenk, Robert W
Wadsworth, 1970
Buku Teks
Coulshed, Veronica, author
Macmillan, 1988
Buku Teks
Loewenberg, Frank
F.E. Peacock Publishers, Inc, 1988
Buku Teks
Healy, Karen, author
Palgrave Macmillan, 2005
Buku Teks