@article{GDZPPN002478552,
title = {A Geometric Theory of Surface Area. III.},
journal = {Monatshefte f\"ur Mathematik},
volume = {77},
year = {1973},
pages = {363-365},
zbl = {0276.50003},
url = {http://dml.mathdoc.fr/item/GDZPPN002478552}
}
Toralballa, L.V. A Geometric Theory of Surface Area. III.. Monatshefte für Mathematik, Tome 77 (1973) pp. 363-365. http://gdmltest.u-ga.fr/item/GDZPPN002478552/