TY  - RPRT
TI  - Probability and sampling.
AU  - J S Bulman
AU  - J F Osborn
PY  - 1989
DO  - 10.1038/sj.bdj.4806749
UR  - https://pubmed.ncbi.nlm.nih.gov/2920136/
ID  - 2920136
ER  -