TY  - RPRT
TI  - Lambert diffuse reflection from general quadric surfaces.
AU  - K W Brand
AU  - F A Spagnolo
PY  - 1967
DO  - 10.1364/josa.57.000452
UR  - https://pubmed.ncbi.nlm.nih.gov/6027820/
ID  - 6027820
ER  -