Gaya APA

X, O. et al (2014). Crush step 1:the ultimate USMLE Step 1 Review . Philadelphia: Saunders-Elsevier.

Gaya MLA

X, O'Connell,Theodore. et al. "Crush step 1:the ultimate USMLE Step 1 Review". Philadelphia: Saunders-Elsevier, 2014. Text.