edited by Barbara Walton Spradley
J.B. Lippincott , 1991
Buku Teks
Freeman, Ruth B., author
W.B. Saunders, 1981
Buku Teks
edited by Barbara Walton Spradley
Little, Brown, 1986
Buku Teks
edited by Allan McNaught
Chapman and Hall , 1991
Buku Teks
Paterson, Robert G. (Robert Gildersleeve), author
McGraw-Hill, 1950
Buku Teks