Παραπομπή σε μορφή APA (7η εκδ.)

Katigbak, A. F. (2003). Almost 80 percent of Pfizer's sildenafil users prefer not to take other ED medications. Philippine Star.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Katigbak, Antonio F. "Almost 80 Percent of Pfizer's Sildenafil Users Prefer Not to Take Other ED Medications." Philippine Star 2003.

Παραπομπή σε μορφή MLA (9th εκδ.)

Katigbak, Antonio F. "Almost 80 Percent of Pfizer's Sildenafil Users Prefer Not to Take Other ED Medications." Philippine Star, 2003.