@article{DE_1993_29_6_a4,
     author = {P. Zecca and P. Nistri and A. V. Frolov},
     title = {Two optimization problems for nonlinear periodic control systems with aftereffect},
     journal = {Differencialʹnye uravneni\^a},
     pages = {943--951},
     publisher = {mathdoc},
     volume = {29},
     number = {6},
     year = {1993},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1993_29_6_a4/}
}