Submitted on: 09 October 2000.
Revised on: 09 January 2001.
Accepted on: 09 February 2001.
___________________BMJ Innovations---BMJ PUBLISHING GROUP
Submitted on: 31 October 2014.
Revised on: 10 February 2015.
Accepted on: 10 April 2015.
___________________BMJ Innovations---BMJ PUBLISHING GROUP
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Submitted on: 06 January 2001.
Revised on: 14 April 2001.
Accepted on: 01 May 2001.
___________________BMJ Innovations---BMJ PUBLISHING GROUP
Submitted on: 26 May 2003.
Revised on: 23 July 2003.
Accepted on: 25 August 2003.
___________________BMJ Innovations---BMJ PUBLISHING GROUP
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Submitted on: 29 May 1999.
Revised on: 22 July 1999.
Accepted on: 23 August 1999.
___________________BMJ Innovations---BMJ PUBLISHING GROUP
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