@article{700061,
     title = {On a theorem of Brunovsky for periodic optimal control},
     booktitle = {Proceedings of Equadiff III},
     series = {GDML\_Books},
     publisher = {Univ. J. E. Purkyn\v e - P\v r\'\i rodov\v edeck\'a fakulta},
     address = {Brno},
     year = {1973},
     pages = {59-69},
     mrnumber = {MR0358485},
     zbl = {0332.49012},
     url = {http://dml.mathdoc.fr/item/700061}
}

Markus, Lawrence. On a theorem of Brunovsky for periodic optimal control, dans Proceedings of Equadiff III, GDML_Books,  (1973), pp. 59-69. http://gdmltest.u-ga.fr/item/700061/