@article{NUMA_1967__10_131800,
     author = {H.J. STOSS},
     title = {Ein {Verfahren} zur {Berechnung} des charakteristischen {Exponenten} der {Differentialgleichung} y'' + (...+ 2...1 cos x + 2..2 cos 2x) y = 0 .},
     journal = {Numerische Mathematik},
     pages = {423--436},
     publisher = {mathdoc},
     volume = {10},
     year = {1967},
     zbl = {0189.48604},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1967__10_131800/}
}