@article{SMZ_2006__47_2_53185,
     author = {Ewert, Janina and Ponomarev, S.P.},
     title = {On essential -variation.},
     journal = {Sibirskij Matematicheskij Zhurnal},
     pages = {473},
     publisher = {mathdoc},
     volume = {47},
     number = {2},
     year = {2006},
     zbl = {1115.26007},
     language = {en},
     url = {https://geodesic-test.mathdoc.fr/item/SMZ_2006__47_2_53185/}
}