@article{UZERU_2005_3_a1,
     author = {T. N. Harutyunyan and G. H. Sahakyan},
     title = {On a spectral problem for a system of partial differential equations},
     journal = {Proceedings of the Yerevan State University. Physical and mathematical sciences},
     pages = {40--46},
     publisher = {mathdoc},
     number = {3},
     year = {2005},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/UZERU_2005_3_a1/}
}