Chang-Ock Lee Jongwoo Lee Dongwoo Sheen A Locking-Free Nonconforming Finite Element Method for Planar Linear Elasticity. 277-291 2003 19 Adv. Comput. Math. 1-3 http://dx.doi.org/10.1023/A:1022838628615 db/journals/adcm/adcm19.html#LeeLS03