We study naturality of the Euler and Helmholtz operators arising in the variational calculus in fibered manifolds with oriented bases.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-cm105-2-1, author = {J. Kurek and W. M. Mikulski}, title = {The Euler and Helmholtz operators on fibered manifolds with oriented bases}, journal = {Colloquium Mathematicae}, volume = {106}, year = {2006}, pages = {171-177}, zbl = {1095.58002}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm105-2-1} }
J. Kurek; W. M. Mikulski. The Euler and Helmholtz operators on fibered manifolds with oriented bases. Colloquium Mathematicae, Tome 106 (2006) pp. 171-177. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm105-2-1/