@article{NUMA_1988__53_1-2_133284,
     author = {Marino Zennaro},
     title = {Natural {Runge-Kutta} and {Projection} {Methods.}},
     journal = {Numerische Mathematik},
     pages = {423--438},
     publisher = {mathdoc},
     volume = {53},
     number = {1-2},
     year = {1988},
     zbl = {0651.65055},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1988__53_1-2_133284/}
}