@article{NUMA_1977__29_132506,
     author = {K. Glashoff and E. Sachs},
     title = {On {Theoretical} and {Numerical} {Aspects} of the {Bang-Bang-Principle.}},
     journal = {Numerische Mathematik},
     pages = {93--114},
     publisher = {mathdoc},
     volume = {29},
     year = {1977},
     zbl = {0353.49011},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1977__29_132506/}
}