@article{CRMATH_2011__349_5-6_269_0,
     author = {Ha{\"\i}m Brezis},
     title = {Comments on two {Notes} by {L.} {Ma} and {X.} {Xu}},
     journal = {Comptes Rendus. Math\'ematique},
     pages = {269--271},
     publisher = {Elsevier},
     volume = {349},
     number = {5-6},
     year = {2011},
     doi = {10.1016/j.crma.2011.01.024},
     language = {en},
}