@article{DE_1989_25_3_a28,
     author = {K. Yu. Kishkis},
     title = {Letter to the editors: {``The} index of the {Bitsadze--Samarski{\v\i}} problem for harmonic functions'' {[Differentsial'nye} {Uravneniya} \textbf{24} (1988), no.~1, 105--110; {MR0930160]}},
     journal = {Differencialʹnye uravneni\^a},
     pages = {546},
     publisher = {mathdoc},
     volume = {25},
     number = {3},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1989_25_3_a28/}
}