TY  - RPRT
TI  - Invariant imbedding and perturbation techniques applied to diffuse reflection from spherical shells
AU  - Bellman, R. E.
AU  - Kagiwada, H. H.
AU  - Kalaba, R. E.
PY  - 1965
UR  - https://ntrs.nasa.gov/citations/19650024263
ID  - 19650024263
ER  -