@article{PORMA_1954__13_3_114736,
     author = {Sternberg, Robert L.},
     title = {Applications of the theory of systems of differential equations to vibrating beams},
     journal = {Portugaliae mathematica},
     pages = {111--120},
     publisher = {mathdoc},
     volume = {13},
     number = {3},
     year = {1954},
     mrnumber = {0068699},
     zbl = {0057.31902},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1954__13_3_114736/}
}