APA
World Health Organization; UNICEF & IVACG, . (1997). Vitamin A supplements. World Health Organization, Geneva: .
Chicago
World Health Organization; UNICEF & IVACG, . 1997. Vitamin A supplements. World Health Organization, Geneva: .
Harvard
World Health Organization; UNICEF & IVACG, . (1997). Vitamin A supplements. World Health Organization, Geneva: .
MLA
World Health Organization; UNICEF & IVACG, . Vitamin A supplements. World Health Organization, Geneva: . 1997.