TY  - RPRT
TI  - Conditioned reinforcement in second-order schedules.
AU  - R T Kelleher
PY  - 1966
DO  - 10.1901/jeab.1966.9-475
UR  - https://pubmed.ncbi.nlm.nih.gov/5964502/
ID  - 5964502
ER  -