APA-referens (7:e uppl.)
Giorgi, J. (2009). Math for wastewater treatment operators grades 1 and 2: A guide to preparing for wastewater treatment operator certification exams. American Water Works Association.
Chicago-referens (17:e uppl.)
Giorgi, John. Math for Wastewater Treatment Operators Grades 1 and 2: A Guide to Preparing for Wastewater Treatment Operator Certification Exams. Denver, Colo.: American Water Works Association, 2009.
MLA-referens (9:e uppl.)
Giorgi, John. Math for Wastewater Treatment Operators Grades 1 and 2: A Guide to Preparing for Wastewater Treatment Operator Certification Exams. American Water Works Association, 2009.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.