@article{10_1007_s10587_011_0048_4,
     author = {Brajer\v{c}{\'\i}k, J\'an},
     title = {Order reduction of the {Euler-Lagrange} equations of higher order invariant variational problems on frame bundles},
     journal = {Czechoslovak Mathematical Journal},
     pages = {1063--1076},
     publisher = {mathdoc},
     volume = {61},
     number = {4},
     year = {2011},
     doi = {10.1007/s10587-011-0048-4},
     mrnumber = {2886257},
     zbl = {1249.53029},
     language = {en},
     url = {https://geodesic-test.mathdoc.fr/articles/10.1007/s10587-011-0048-4/}
}