Cita APA (7th ed.)

HAMMER, W. (1989). Occupational safety management and engineering (Ed.4.). Prentice Hall.

Cita Chicago (17th ed.)

HAMMER, Willie. Occupational Safety Management and Engineering. Ed.4. New Jersey: Prentice Hall, 1989.

Cita MLA (9th ed.)

HAMMER, Willie. Occupational Safety Management and Engineering. Ed.4. Prentice Hall, 1989.