Helmer, R. G. (1998). Time management: For engineers and constructors. American Society of Civil Engineers.
Chicago-Zitierstil (17. Ausg.)Helmer, Ray G. Time Management: For Engineers and Constructors. Washington, D.C: American Society of Civil Engineers, 1998.
MLA-Zitierstil (9. Ausg.)Helmer, Ray G. Time Management: For Engineers and Constructors. American Society of Civil Engineers, 1998.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.