@article{10_1007_s10492_009_0020_x,
     author = {Kar\'atson, J\'anos and Korotov, Sergey},
     title = {Sharp upper global a posteriori error estimates for nonlinear elliptic variational problems},
     journal = {Applications of Mathematics},
     pages = {297--336},
     publisher = {mathdoc},
     volume = {54},
     number = {4},
     year = {2009},
     doi = {10.1007/s10492-009-0020-x},
     mrnumber = {2520833},
     zbl = {1212.65249},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.1007/s10492-009-0020-x/}
}