@article{JRAM_1965__217_150657,
     author = {Carlos R. Cavoti},
     title = {The calculus of variations approach to systems optimization.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {1--48},
     publisher = {mathdoc},
     volume = {217},
     year = {1965},
     zbl = {0133.36304},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1965__217_150657/}
}