1. Chute profile for maximum exit velocity in gravity flow of granular material;Charlton;J. agric. Engng Res.,1970
2. An investigation of the gravity flow of non-cohesive granular materials through discharge chutes;Roberts;Trans. ASME, J. Engng Ind.,1969
3. The Calculus of Variations;Forsyth,1960
4. Variational Methods in Control Engineering;Noton,1965
5. Dynamic Programming;Aris,1963