Walker, Warren F., author
W.H. Freeman, 1974
Buku Teks
Walker, Warren F.
Saunders College Pub., 1986
Buku Referensi
Walker, Warren F.
Saunders College, 1980
Buku Teks
Wischnitzer, Saul, author
W.H. Freeman, 1972
Buku Teks
Walker, Warren F.
W.B. Saunders, 1975
Buku Teks