TY  - BOOK
AU  - Petrides,George A.
TI  - A field guide to trees and shrubs: northeastern and north-central United States and southeastern and south-central Canada 
T2  - The Peterson field guide series
SN  - 0-395-17579-8
AV  - QK482 P48
PY  - 1986///
N1  - Incluye bibliografia
ER  -