(1988). Vitamin A supplemnsts Aguide to their use in the treatment and prevention of vitamin A deficiency and xerophthalmia. World health organization.
Chicago Style aipamenaVitamin A Supplemnsts Aguide to Their Use in the Treatment and Prevention of Vitamin A Deficiency and Xerophthalmia. Ginebra: World health organization, 1988.
MLA aipamenaVitamin A Supplemnsts Aguide to Their Use in the Treatment and Prevention of Vitamin A Deficiency and Xerophthalmia. World health organization, 1988.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.