@article{IM_1975__29_142340,
     author = {Harold Donnelly},
     title = {Heat {Equation} and the {Volume} of {Tubes.}},
     journal = {Inventiones mathematicae},
     pages = {239--244},
     publisher = {mathdoc},
     volume = {29},
     year = {1975},
     zbl = {0293.35035},
     url = {http://geodesic.mathdoc.fr/item/IM_1975__29_142340/}
}