TY  - BOOK
AU  - Petrides, George A.
TI  - A field guide to western trees: : western United States and Canada
T2  - The Peterson fiel guide series
U1  - 582.16 
PY  - 1992///
CY  - Boston, Mass.
PB  - Houghton Mifflin
KW  - Árboles
KW  - Canada
KW  - Clasificación
KW  - E.U.A
N1  - 59-219
ER  -