@article{M2AN_2006__40_1_149_0,
     author = {Sandberg, Mattias and Szepessy, Anders},
     title = {Convergence rates of symplectic {Pontryagin} approximations in optimal control theory},
     journal = {ESAIM: Mod\'elisation math\'ematique et analyse num\'erique},
     pages = {149--173},
     publisher = {EDP-Sciences},
     volume = {40},
     number = {1},
     year = {2006},
     doi = {10.1051/m2an:2006002},
     mrnumber = {2223508},
     zbl = {1091.49027},
     language = {en},
     url = {http://archive.numdam.org/articles/10.1051/m2an:2006002/}
}