Poole, Ernest
Thomas Y. Crowell , 1949
Buku Teks
Poole, Ernest
New York, Thomas Y.Creweel, 1949
Buku Teks
Bormann, Ernest G., author
Burgess Publishing, 1972
Buku Teks
Poole, Colin F.
Elsevier, 1991
Buku Teks
Poole, I. D.
Bernard Babani, 1992
Buku Teks