@article{RM_1973_28_1_a1,
     author = {A. V. Efimov and V. P. Potapov},
     title = {$J$-expanding mtrix functions and their role in the analytical theory of electrical circuits},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {69--140},
     publisher = {mathdoc},
     volume = {28},
     number = {1},
     year = {1973},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1973_28_1_a1/}
}