APA
World Health Organization, . (1988). Essential drugs for primary health care. World Health Organization, New Delhi: .
Chicago
World Health Organization, . 1988. Essential drugs for primary health care. World Health Organization, New Delhi: .
Harvard
World Health Organization, . (1988). Essential drugs for primary health care. World Health Organization, New Delhi: .
MLA
World Health Organization, . Essential drugs for primary health care. World Health Organization, New Delhi: . 1988.