Exploring user perceptions of occasional and controlled heroin use: A follow-up study / JRF, 5 July 2007
PDF - http://www.jrf.org.uk/bookshop/eBooks/2079-heroin-controlled-drugs.pdf
Tim McSweeney and Paul J. Turnbull
"This study follows up earlier research on occasional and controlled patterns of heroin use
in order to examine how – if at all – this group’s use of the drug changed over an extended
period of time."