@Article{ bar06, author = { Barchiesi, Marco }, title = { Loss of polyconvexity by homogenization: a new example }, journal = { Calc. Var. Partial Differential Equations }, year = { 2007 }, volume = { 30 }, number = { 2 }, pages = { 215-230 }, URL = { http://cvgmt.sns.it/paper/549/ }, note = { cvgmt preprint} }