@article{10_21136_AM_1969_103236,
     author = {Hlav\'a\v{c}ek, Ivan},
     title = {Variational principles for parabolic equations},
     journal = {Applications of Mathematics},
     pages = {278--297},
     publisher = {mathdoc},
     volume = {14},
     number = {4},
     year = {1969},
     doi = {10.21136/AM.1969.103236},
     mrnumber = {0255988},
     zbl = {0182.13803},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/AM.1969.103236/}
}