Gaya APA
Friend, M, A., Kohn, J, P. (2007).
FUNDAMENTALS OF OCCUPATIONAL SAFETY AND HEALTH (Fourth Edition).
United states of America:
GOVERMENT INSTITUTES.
Gaya MLA
Friend, Mark, A., Kohn, James, P.
"FUNDAMENTALS OF OCCUPATIONAL SAFETY AND HEALTH".
Fourth Edition
United states of America:
GOVERMENT INSTITUTES,
2007.
Text.