@Article{ ghigob02, author = { Ghisi, Marina and Gobbino, Massimo }, title = { The monopolist's problem: existence, relaxation and approximation }, journal = { Calc. Var. Partial Differential Equations }, year = { 2005 }, volume = { 24 }, number = { 1 }, pages = { 111-129 }, URL = { http://cvgmt.sns.it/paper/185/ }, note = { cvgmt preprint} }