TY  - BOOK
AU  - Critchfield William B
TI  - Geographic variation in pinus contorta
T2  - Maria moors cabot foundation publication; 3
U1  - I651:12, J7 
PY  - 1957///
CY  - Cambridge
PB  - Harvard University        
KW  -  Gymnosperms
KW  - Botany
ER  -