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Submitted on: 17 July 2018.
Revised on: 07 October 2018.
Accepted on: 28 October 2018.
___________________BMC Geriatrics---BMC
Submitted on: 14 August 2013.
Revised on: 20 September 2013.
Accepted on: 01 October 2013.
___________________BMC Geriatrics---BMC
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