APA (7th ed.) Zitazioa

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

Chicago Style (17th ed.) Zitazioa

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

MLA (9th ed.) Zitazioa

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