@article{IVM_2007_10_a2,
     author = {V. V. Goldberg and V. V. Lychagin},
     title = {Abelian equations and rank problems for planar webs},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {40--75},
     publisher = {mathdoc},
     number = {10},
     year = {2007},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_2007_10_a2/}
}