by Akira Takanashi [and others]
The Japan Institute of Labour , 1999
Buku Teks
Artikel Jurnal
Bennet-Alexander, Dawn, author
Irwin/McGraw-Hill, 2004
Buku Teks
Jackson, Grdon E., author
Prentice-Hall, 1993
Buku Referensi
Painter, Richard W., author
Pluto Press, 1993
Buku Teks