@article{M2AN_1970__4_2_3_0,
     author = {Niedereichholz, J.},
     title = {On the connection between the theory of signal flow graphs and the theory of directed graphs},
     journal = {ESAIM: Mathematical Modelling and Numerical Analysis },
     pages = {3--9},
     publisher = {Dunod},
     address = {Paris},
     volume = {4},
     number = {R2},
     year = {1970},
     zbl = {0211.52401},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/M2AN_1970__4_2_3_0/}
}