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Submitted on: 06 November 2010.
Revised on: 23 January 2011.
Accepted on: 17 February 2011.
___________________Applied General Topology---UNIV POLITECNICA VALENCIA, EDITORIAL UPV
Submitted on: 29 January 2022.
Revised on: 26 May 2022.
Accepted on: 12 June 2022.
___________________Applied General Topology---UNIV POLITECNICA VALENCIA, EDITORIAL UPV
Submitted on: 27 February 2021.
Revised on: 24 April 2021.
Accepted on: 06 June 2021.
___________________Applied General Topology---UNIV POLITECNICA VALENCIA, EDITORIAL UPV