Submitted on: 17 May 2022.
Revised on: 24 June 2022.
Accepted on: 18 August 2022.
___________________Harm Reduction Journal---BMC
Submitted on: 19 October 2011.
Revised on: 31 December 2011.
Accepted on: 24 February 2012.
___________________Harm Reduction Journal---BMC
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Submitted on: 16 May 2010.
Revised on: 11 September 2010.
Accepted on: 27 October 2010.
___________________Harm Reduction Journal---BMC
http://reply.papertrans.cn/2/111/11032/11032-25.png
Submitted on: 08 September 2001.
Revised on: 30 November 2001.
Accepted on: 02 January 2002.
___________________Harm Reduction Journal---BMC
Submitted on: 29 December 2011.
Revised on: 01 March 2012.
Accepted on: 26 April 2012.
___________________Harm Reduction Journal---BMC
Submitted on: 08 May 2004.
Revised on: 09 June 2004.
Accepted on: 30 June 2004.
___________________Harm Reduction Journal---BMC
Submitted on: 11 May 2018.
Revised on: 02 July 2018.
Accepted on: 02 August 2018.
___________________Harm Reduction Journal---BMC
Submitted on: 06 March 2013.
Revised on: 04 April 2013.
Accepted on: 20 May 2013.
___________________Harm Reduction Journal---BMC