TY  - RPRT
TI  - Improving response rates with incentives.
AU  - C Rissel
PY  - 1989
DO  - 10.5694/j.1326-5377.1989.tb136549.x
UR  - https://pubmed.ncbi.nlm.nih.gov/2716671/
ID  - 2716671
ER  -