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Submitted on: 17 August 2008.
Revised on: 08 October 2008.
Accepted on: 22 November 2008.
___________________Journal of Gerontology and Geriatrics
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Submitted on: 30 October 2003.
Revised on: 21 February 2004.
Accepted on: 15 April 2004.
___________________Journal of Gerontology and Geriatrics
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Submitted on: 26 February 2006.
Revised on: 15 May 2006.
Accepted on: 12 June 2006.
___________________Journal of Gerontology and Geriatrics
Submitted on: 25 February 2001.
Revised on: 27 May 2001.
Accepted on: 16 June 2001.
___________________Journal of Gerontology and Geriatrics