@article{Arbia2012,
author = {Arbia, G. and Espa, G. and Giuliani, D. and Mazzitelli, A.},
title= {Clusters of firms in an inhomogeneous space: The high-tech industries in Milan },
year = {2012},
URL = {10.1016/j.econmod.2011.01.012},
journal = {Economic Modelling },
volume = {29},
number = {1},
pages = {3--11},
}