@article{ZNSL_1987_165_a16,
     author = {S. Tleukenov},
     title = {Characteristic matrix of a periodically inhomogeneous layer},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {177--181},
     year = {1987},
     volume = {165},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1987_165_a16/}
}