@article{COCV_2020__26_1_A99_0,
     author = {Chittaro, Francesca C. and Poggiolini, Laura},
     title = {Singular extremals in $L^1$-optimal control problems: sufficient optimality conditions},
     journal = {ESAIM: Control, Optimisation and Calculus of Variations},
     publisher = {EDP-Sciences},
     volume = {26},
     year = {2020},
     doi = {10.1051/cocv/2020023},
     mrnumber = {4185063},
     zbl = {1471.49004},
     language = {en},
     url = {http://www.numdam.org/articles/10.1051/cocv/2020023/}
}