Citazione Stile APA (7a Edizione)

Helmer, R. G. (1998). Time management: For engineers and constructors. American Society of Civil Engineers.

Citazione stile Chigago Style (17a edizione)

Helmer, Ray G. Time Management: For Engineers and Constructors. Washington, D.C: American Society of Civil Engineers, 1998.

Citatione MLA (9a ed.)

Helmer, Ray G. Time Management: For Engineers and Constructors. American Society of Civil Engineers, 1998.