Cryptogamic Botany Bryophytes And Pteridophytes - Smith, Gilbert M. (New York and London McGraw-Hill Book Inc., 1938)
Zb mean Botany Page 500-509 (Acc. No. Zb1-Zb343) & Page 578-581 (Acc. No. Zb344-Zb468)
Keywords: Botany-Bryophytes and Pteridophytes