Submitted on: 21 September 2012.
Revised on: 24 December 2012.
Accepted on: 24 January 2013.
___________________AJIDD-American Journal on Intellectual and Developmental Disabilities
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Submitted on: 04 May 2006.
Revised on: 05 July 2006.
Accepted on: 20 July 2006.
___________________AJIDD-American Journal on Intellectual and Developmental Disabilities
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Submitted on: 16 December 2008.
Revised on: 08 April 2009.
Accepted on: 06 May 2009.
___________________AJIDD-American Journal on Intellectual and Developmental Disabilities
Submitted on: 18 November 2000.
Revised on: 03 March 2001.
Accepted on: 30 March 2001.
___________________AJIDD-American Journal on Intellectual and Developmental Disabilities
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Submitted on: 02 December 2003.
Revised on: 14 March 2004.
Accepted on: 23 April 2004.
___________________AJIDD-American Journal on Intellectual and Developmental Disabilities
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