TY  - RPRT
TI  - LEDs: convenient, inexpensive sources for visual experimentation.
AU  - R W Nygaard
AU  - T E Frumkes
PY  - 1982
DO  - 10.1016/0042-6989(82)90190-0
UR  - https://pubmed.ncbi.nlm.nih.gov/7112942/
ID  - 7112942
ER  -