TY  - BOOK
AU  - Darwin,Charles Robert
TI  - The origin of species: by means of natural selection or the preservation of favoured races in the struggle for life 
T2  - Mentor book
U1  - 575 
PY  - 1963///
CY  - New York, NY.
PB  - Mentor
KW  - Evolución
KW  - Selección natural
ER  -