@article{NUMA_1986__50_133147,
     author = {E. Gekeler and R. Widman},
     title = {On the {Order} {Conditions} of {Runge-Kutta} {Methods} with {Higher} {Derivatives.}},
     journal = {Numerische Mathematik},
     pages = {183--204},
     publisher = {mathdoc},
     volume = {50},
     year = {1986},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1986__50_133147/}
}