@article{MAN_1974__209_162584,
     author = {R.M. Redheffer and W. Walter},
     title = {The {Total} {Variation} of {Solutions} of {Parabolic} {Differential} {Equations} and a {Maximum} {Principle} in {Unbounded} {Domains.}},
     journal = {Mathematische Annalen},
     pages = {57--68},
     publisher = {mathdoc},
     volume = {209},
     year = {1974},
     zbl = {0267.35053},
     url = {http://geodesic.mathdoc.fr/item/MAN_1974__209_162584/}
}