@article{SM_2008_199_10_a6,
     author = {G. I. Sharygin},
     title = {Local formulae for characteristic
},
     journal = {Sbornik. Mathematics},
     pages = {1547--1577},
     publisher = {mathdoc},
     volume = {199},
     number = {10},
     year = {2008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2008_199_10_a6/}
}