@article{UZERU_2009_3_a0,
     author = {I. G. Khachatryan},
     title = {On some formulas for the index of linear bounded operator},
     journal = {Proceedings of the Yerevan State University. Physical and mathematical sciences},
     pages = {3--9},
     publisher = {mathdoc},
     number = {3},
     year = {2009},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/UZERU_2009_3_a0/}
}