TY  - BOOK
AU  - Skinner, Burrhus Frederic.
TI  - Contingencies of reinforcement ; a theorical analysis
T2  - The century paychology series
U1  - 150 
PY  - 1969///
CY  - New York
PB  - Appleton-Century-Crofts
KW  - Conducta (Psicología)
ER  -