@article{SIGMA_2008_4_a31,
     author = {George Svetlichny},
     title = {Equivariance, {Variational} {Principles,} and the {Feynman} {Integral}},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2008},
     volume = {4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2008_4_a31/}
}