APA-viite (7. p.)

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

Chicago-viite (17. p.)

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

MLA-viite (9. p.)

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