@article{GDZPPN002180979,
title = {The calculus of variations approach to systems optimization.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {218},
year = {1965},
pages = {1-48},
zbl = {0133.36304},
url = {http://dml.mathdoc.fr/item/GDZPPN002180979}
}
Cavoti, Carlos R. The calculus of variations approach to systems optimization.. Journal für die reine und angewandte Mathematik, Tome 218 (1965) pp. 1-48. http://gdmltest.u-ga.fr/item/GDZPPN002180979/