@article{COCV_2018__24_4_1429_0,
     author = {Mannucci, Paola and Marchi, Claudio and Tchou, Nicoletta},
     title = {Singular perturbations for a subelliptic operator},
     journal = {ESAIM: Control, Optimisation and Calculus of Variations},
     pages = {1429--1451},
     publisher = {EDP-Sciences},
     volume = {24},
     number = {4},
     year = {2018},
     doi = {10.1051/cocv/2017063},
     zbl = {1414.35019},
     mrnumber = {3922437},
     language = {en},
     url = {http://www.numdam.org/articles/10.1051/cocv/2017063/}
}