APA
n.a, . (1990). The United States pharmacopeia the national formulary USP xxii. USP convention Inc, Rockville: .
Chicago
n.a, . 1990. The United States pharmacopeia the national formulary USP xxii. USP convention Inc, Rockville: .
Harvard
n.a, . (1990). The United States pharmacopeia the national formulary USP xxii. USP convention Inc, Rockville: .
MLA
n.a, . The United States pharmacopeia the national formulary USP xxii. USP convention Inc, Rockville: . 1990.