TY  - RPRT
TI  - Preference for mixed-interval versus fixed-interval schedules.
AU  - M C Davison
PY  - 1969
DO  - 10.1901/jeab.1969.12-247
UR  - https://pubmed.ncbi.nlm.nih.gov/16811349/
ID  - 16811349
ER  -