@article{SJVM_2012_15_2_a11,
     author = {H. Calandra and S. Gratton and R. Lago and X. Pinel and X. Vasseur},
     title = {Two-level preconditioned {Krylov} subspace methods for the solution of three-dimensional heterogeneous {Helmholtz} problems in seismics},
     journal = {Sibirskij \v{z}urnal vy\v{c}islitelʹnoj matematiki},
     pages = {213--221},
     publisher = {mathdoc},
     volume = {15},
     number = {2},
     year = {2012},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/SJVM_2012_15_2_a11/}
}