Levring, Tore. Marine algae : a survey of research and utilization / by Tore Levring, Heinz A. Hoppe, Otto J. Schmid. - Hamburg : Cram, de Gruyter, 1969. - 421 p. : ill. ; 25 cm. - Botanica marina handbooks ; v. 1 . Includes bibliographies. Subjects--Topical Terms: Marine algae.