TY  - RPRT
TI  - Performance on variable-interval schedules arranged singly and concurrently.
AU  - M C Davison
AU  - I W Hunter
PY  - 1976
DO  - 10.1901/jeab.1976.25-335
UR  - https://pubmed.ncbi.nlm.nih.gov/16811917/
ID  - 16811917
ER  -