Gaya APA

Offit, P, A., Bell, L, M. (1999). Vaccines: What Every Parent Should Know revised edition . NewYork: John Wiley & Sons.

Gaya MLA

Offit, Paul, A.., Bell, Louis, M.. "Vaccines: What Every Parent Should Know revised edition". NewYork: John Wiley & Sons, 1999. Teks (Text).