TY  - RPRT
TI  - Task difficulty increases thresholds of rewarding brain stimulation.
AU  - G Fouriezos
AU  - C Bielajew
AU  - W Pagotto
PY  - 1990
DO  - 10.1016/0166-4328(90)90066-n
UR  - https://pubmed.ncbi.nlm.nih.gov/2310490/
ID  - 2310490
ER  -