A piecewise P2-nonconforming quadrilateral finite element Imbunm Kim, Zhongxuan Luo, Zhaoliang Meng, Hyun Nam, Chunjae Park and Dongwoo Sheen ESAIM: M2AN, 47 3 (2013) 689-715 Published online: 04 March 2013 DOI: 10.1051/m2an/2012044