RT Journal Article SR Electronic T1 Low rates of p24 antigen detection using a fourth-generation point of care HIV test JF Sexually Transmitted Infections JO Sex Transm Infect FD BMJ Publishing Group Ltd SP 178 OP 179 DO 10.1136/sti.2010.042564 VO 87 IS 2 A1 Julie Fox A1 Helen Dunn A1 Siobhan O'Shea YR 2011 UL http://sti.bmj.com/content/87/2/178.abstract AB