TY  - RPRT
TI  - Incentive effects and competing response models.
AU  - D Birch
AU  - F P Valle
PY  - 1967
DO  - 10.2466/pr0.1967.20.1.263
UR  - https://pubmed.ncbi.nlm.nih.gov/6037804/
ID  - 6037804
ER  -