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Submitted on: 18 October 2006.
Revised on: 20 November 2006.
Accepted on: 26 November 2006.
Perspectivas em Ciencia da Informacao
Submitted on: 18 October 2006.
Revised on: 25 November 2006.
Accepted on: 19 December 2006.
NULL
Submitted on: 27 February 2011.
Revised on: 03 April 2011.
Accepted on: 16 April 2011.
Perspectivas em Ciencia da Informacao
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