Human Papilloma Vaccines: Questions & Answers (2018). National Cancer Institute Member Services.
Citazione stile Chigago Style (17a edizione)Human Papilloma Vaccines: Questions & Answers (2018). National Cancer Institute Member Services.
Citatione MLA (9a ed.)Human Papilloma Vaccines: Questions & Answers (2018). National Cancer Institute Member Services.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.