Bir, S.S.. Aspects of Plant Sciences, vol.6: Pteridophytes, their Morphology, Cytology, Taxonomy and Phylogeny / - 1st ed / - New Delhi : today and tomorrpw's Printers & Publishers , 1982 - viii, 253p ; Subjects--Topical Terms: Botany Dewey Class. No.: I4:2 / M3