Brito, E. P. Z., L. A. L. Brito, E. C. Porto, and M. E. Szilagyi. “The Relationship Between Productive Agglomeration and Growth: The Application of a Multi-Level Model in the Industrial Sector of São Paulo State, Brazil”. Journal of Contemporary Administration, Vol. 14, no. 4, 1, pp. 615-32, doi:10.1590/S1415-65552010000400004.