TY - JOUR AU - Wei, Ting AU - Xian, Jun TI - Variational method for a backward problem for a time-fractional diffusion equation JO - ESAIM: Mathematical Modelling and Numerical Analysis PY - 2019 SP - 1223 EP - 1244 VL - 53 IS - 4 PB - EDP-Sciences UR - http://www.numdam.org/articles/10.1051/m2an/2019019/ DO - 10.1051/m2an/2019019 LA - en ID - M2AN_2019__53_4_1223_0 ER -