Armstrong, Micahel, author
Kogan Page, 2005
Buku Teks
Armstrong, Micahel, author
Kogan Page, 2005
Buku Teks
Polse, Frans
Crest Publishing House, 1999
Buku Teks
Lanham, E., author
McGraw-Hill, 1955
Buku Teks
Morris, J. Walker
Heinemann , 1973
Buku Teks