@article{DAN_1957_112_5_a2,
     author = {Z. I. Biglov},
     title = {An expansion in eigenfunctions of a system of second order differential equations},
     journal = {Doklady Akademii Nauk},
     pages = {797--799},
     publisher = {mathdoc},
     volume = {112},
     number = {5},
     year = {1957},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1957_112_5_a2/}
}