@Article{ NovOka15, author = { Novaga, Matteo and Okabe, Shinya }, title = { The two obstacle problem for the parabolic biharmonic equation }, journal = { Nonlinear Analysis: Theory, Methods & Appl. }, year = { 2016 }, volume = { 136 }, pages = { 215-233 }, URL = { http://cvgmt.sns.it/paper/2785/ }, note = { cvgmt preprint} }