World Health Organization. (2003). State of the world's vaccines and immunization. World Health Organisation.
استشهاد بنمط شيكاغوWorld Health Organization. State of the World's Vaccines and Immunization. Geneva: World Health Organisation, 2003.
MLA استشهادWorld Health Organization. State of the World's Vaccines and Immunization. World Health Organisation, 2003.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.