@incollection{MSMF_1979__60__95_0,
     author = {Lebourg, G\'erard},
     title = {Perturbed optimization problems in {Banach} spaces},
     booktitle = {Analyse non convexe (Pau, 1977)},
     series = {M\'emoires de la Soci\'et\'e Math\'ematique de France},
     pages = {95--111},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {60},
     year = {1979},
     doi = {10.24033/msmf.263},
     mrnumber = {82c:49005},
     zbl = {0417.90089},
     url = {http://www.numdam.org/articles/10.24033/msmf.263/}
}