TY  - RPRT
TI  - Measuring second-order selection bias in a work site health program.
AU  - M Sepulveda
AU  - A Goetz
AU  - J Grana
PY  - 1994
DO  - 10.1097/00043764-199403000-00010
UR  - https://pubmed.ncbi.nlm.nih.gov/8195903/
ID  - 8195903
ER  -