TY  - RPRT
TI  - Statistics at square one. II--Mean from frequency distribution.
AU  - T D Swinscow
PY  - 1976
DO  - 10.1136/bmj.1.6021.1325
UR  - https://pubmed.ncbi.nlm.nih.gov/1268681/
ID  - 1268681
ER  -