TY  - RPRT
TI  - A multi-option program for learning basic addition facts: case studies and an experimental report.
AU  - G A Jones
AU  - C A Thornton
AU  - M A Toohey
DO  - 10.1177/002221948501800603
UR  - https://pubmed.ncbi.nlm.nih.gov/4020285/
ID  - 4020285
ER  -