@article{10_4064_cm124_2_11,
     author = {Valentino Magnani},
     title = {An area formula in metric spaces},
     journal = {Colloquium Mathematicum},
     pages = {275--283},
     publisher = {mathdoc},
     volume = {124},
     number = {2},
     year = {2011},
     doi = {10.4064/cm124-2-11},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm124-2-11/}
}