TY  - BOOK
AU  - Erdtman, G.
AU  - Sorsa, P.
TI  - Pollen and Spore Morphology/ Plant Taxonomy: : Pteridophyta
SN  - 000
U1  - 581.04 
PY  - 1971///
CY  - Stockholm
PB  - Almqvist & Wiksell
ER  -