Gaya APA
Asfahl, C, R., Riske, D, W. (2010).
Industrial Safety and Health Management, Sixth Edition (Sixth Edition).
USA:
Prentice Hall.
Gaya MLA
Asfahl, C., Ray., Riske, David, W..
"Industrial Safety and Health Management, Sixth Edition".
Sixth Edition
USA:
Prentice Hall,
2010.
Book.