RT Journal Article SR Electronic T1 Comparison of teenagers’ early same sex and heterosexual behaviour in the UK: data from the share and RIPPLE studies JF Journal of Epidemiology and Community Health JO J Epidemiol Community Health FD BMJ Publishing Group Ltd SP 39 OP 39 DO 10.1136/jech.2009.096719m VO 63 IS Suppl 2 A1 Parkes, A. A1 Strange, V. A1 Wight, D. A1 Henderson, M. A1 Buston, K. YR 2009 UL http://jech.bmj.com/content/63/Suppl_2/39.abstract AB