Παραπομπή σε μορφή APA (7η εκδ.)

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.

Παραπομπή σε μορφή Chicago (17η εκδ.)

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.

Παραπομπή σε μορφή MLA (9th εκδ.)

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.