1. Diffuse reflection by a semi-infinite atmosphere;Horak;Astrophys. J.,1961
2. Radiative Transfer;Chandrasekhar,1950
3. also Dover Publications, New York (1960).
4. Reflection by semi-infinite diffusers;Giovanelli;Optica Acta,1955
5. Numerical solutions for multiple, anisotropic scattering;Chu,1963