http://dx.doi.org/10.1136/bjsm.2002.003020 | | | | DOI Link |
http://bjsm.bmj.com/content/38/2/168.full | 10/22/2014 | | Item is within a limited-access website | |
http://bjsm.bmj.com/content/38/2/168.full.pdf | 10/22/2014 | PDF Reader | Item is within a limited-access website | |