TY  - RPRT
TI  - Preference for qualitatively different reinforcers.
AU  - V Hollard
AU  - M C Davison
PY  - 1971
DO  - 10.1901/jeab.1971.16-375
UR  - https://pubmed.ncbi.nlm.nih.gov/16811552/
ID  - 16811552
ER  -