TY  - RPRT
TI  - Conditional discrimination and equivalence relations: Control by negative stimuli.
AU  - C Johnson
AU  - M Sidman
PY  - 1993
DO  - 10.1901/jeab.1993.59-333
UR  - https://pubmed.ncbi.nlm.nih.gov/16812689/
ID  - 16812689
ER  -