Voigt, N. R. (2006). Six-minute solutions for civil PE exam: Transportation problems (Second edition.). Professional Publications.
Chicago-referens (17:e uppl.)Voigt, Norman R. Six-minute Solutions for Civil PE Exam: Transportation Problems. Second edition. Belmont, CA: Professional Publications, 2006.
MLA-referens (9:e uppl.)Voigt, Norman R. Six-minute Solutions for Civil PE Exam: Transportation Problems. Second edition. Professional Publications, 2006.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.