TY  - RPRT
TI  - Choice in a variable environment: every reinforcer counts.
AU  - M Davison
AU  - W M Baum
PY  - 2000
DO  - 10.1901/jeab.2000.74-1
UR  - https://pubmed.ncbi.nlm.nih.gov/10966094/
ID  - 10966094
ER  -