Norstog, Knut, 1921-. Plant biology / Knut Norstog, Robert W. Long. - Philadelphia : Saunders, c1976. - vi, 585 p. : ill. ; 27 cm. Includes index. ISBN: 072166864X LCCN: 75000297 Subjects--Topical Terms: Botany. LC Class. No.: QK47 QK47 / .N66 1976 / .N66 Dewey Class. No.: 581