Submitted on: 02 January 1999.
Revised on: 30 March 1999.
Accepted on: 09 April 1999.
___________________Geofocus-Revista Internacional de Ciencia y TecnologIa de la InformaciOn GeogrAfica
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Submitted on: 28 May 2023.
Revised on: 13 September 2023.
Accepted on: 28 September 2023.
___________________Geofocus-Revista Internacional de Ciencia y TecnologIa de la InformaciOn GeogrAfica
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Submitted on: 19 June 2017.
Revised on: 24 July 2017.
Accepted on: 07 August 2017.
___________________Geofocus-Revista Internacional de Ciencia y TecnologIa de la InformaciOn GeogrAfica
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