TY  - RPRT
TI  - Opening the grey box.
AU  - R J Douglas
AU  - K A Martin
PY  - 1991
DO  - 10.1016/0166-2236(91)90139-l
UR  - https://pubmed.ncbi.nlm.nih.gov/1719675/
ID  - 1719675
ER  -