Symposiumon structure, nomenclature and classification of pollen and spores / Birbal sahni Institute of Palaeobotany - Ranchi: Birbal Sahni Institute of Palaeobotany, 1974 - 73p. - Special publication 4 . Subjects--Topical Terms: Science Universal Decimal Class. No.: 581.331:582.2/.3(082.2) / L4