TY - JOUR AU - G. I. Shishkin TI - Grid approximations with an improved rate of convergence for singularly perturbed elliptic equations in domains with characteristic boundaries JO - Sibirskij žurnal vyčislitelʹnoj matematiki PY - 2002 SP - 71 EP - 92 VL - 5 IS - 1 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/SJVM_2002_5_1_a6/ LA - ru ID - SJVM_2002_5_1_a6 ER -