@article{ZNSL_1981_101_a4,
     author = {V. S. Gerdjikov and P. P. Kulish},
     title = {Expansion in {\textquotedblleft}square{\textquotedblright} eigenfunctions of matrix linear system},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {46--63},
     year = {1981},
     volume = {101},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1981_101_a4/}
}