TY  - RPRT
TI  - Conservation, choice, and the concurrent fixed-ratio schedule.
AU  - N Shapiro
AU  - J Allison
PY  - 1978
DO  - 10.1901/jeab.1978.29-211
UR  - https://pubmed.ncbi.nlm.nih.gov/16812049/
ID  - 16812049
ER  -