@article{SJVM_2005_8_3_a1,
     author = {A. B. Andreev and M. S. Petrov and T. D. Todorov},
     title = {General results for lumped mass approximation of isoparametric eigenvalue problem on triangular meshes},
     journal = {Sibirskij \v{z}urnal vy\v{c}islitelʹnoj matematiki},
     pages = {189--205},
     publisher = {mathdoc},
     volume = {8},
     number = {3},
     year = {2005},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SJVM_2005_8_3_a1/}
}