@article{10_4064_sm_72_2_151_159,
     author = {Jean Ollagnier and Didier Pinchon},
     title = {The variational principle},
     journal = {Studia Mathematica},
     pages = {151--159},
     publisher = {mathdoc},
     volume = {72},
     number = {2},
     year = {1982},
     doi = {10.4064/sm-72-2-151-159},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-72-2-151-159/}
}