TY  - RPRT
TI  - Subgroups A1 and A2: qualitative and/or quantitative distinctions?
AU  - J F Mohn
AU  - R K Cunningham
PY  - 1980
DO  - 10.3109/08820138009065986
UR  - https://pubmed.ncbi.nlm.nih.gov/6156891/
ID  - 6156891
ER  -