TY  - BOOK
AU  - Geesink R
AU  -  Leeuwenberg A J M
TI  - Thonner's analytical key to the families of flowering plants
U1  - I5:11M63x, M1 
PY  - 1981///
CY  - The Hague
PB  - Hugue Leiden University Press      
KW  -  Flowering plant
KW  - Botany
ER  -