@article{SM_1974_24_4_a3,
     author = {B. V. Fedosov},
     title = {An analytic formula for the index of an elliptic boundary-value {problem.~II}},
     journal = {Sbornik. Mathematics},
     pages = {511--535},
     publisher = {mathdoc},
     volume = {24},
     number = {4},
     year = {1974},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1974_24_4_a3/}
}