@article{KYB_1993_29_5_a4,
     author = {Geerts, Ton},
     title = {Free end-point linear-quadratic control subject to implicit continuous- time systems: {Necessary} and sufficient conditions for solvability},
     journal = {Kybernetika},
     pages = {431--438},
     year = {1993},
     volume = {29},
     number = {5},
     mrnumber = {1264876},
     zbl = {0807.93033},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/KYB_1993_29_5_a4/}
}