TY  - RPRT
TI  - A category theory approach to cognitive development.
AU  - G S Halford
AU  - W H Wilson
PY  - 1980
DO  - 10.1016/0010-0285(80)90014-6
UR  - https://pubmed.ncbi.nlm.nih.gov/7408434/
ID  - 7408434
ER  -