@Article{ BucButNit17, author = { Bucur, Dorin and Buttazzo, Giuseppe and Nitsch, Carlo }, title = { Two optimization problems in thermal insulation }, journal = { Notices Amer. Math. Soc. }, year = { 2017 }, doi = { http://dx.doi.org/10.1090/noti1557 }, volume = { 64 }, number = { 8 }, pages = { 830-835 }, URL = { http://cvgmt.sns.it/paper/3554/ }, note = { cvgmt preprint} }