RT Journal Article SR Electronic T1 Designing out violence and aggression JF Emergency Medicine Journal JO Emerg Med J FD BMJ Publishing Group Ltd and the British Association for Accident & Emergency Medicine SP 172 OP 172 DO 10.1136/emermed-2011-200957 VO 29 IS 3 A1 Geoffrey Hughes YR 2012 UL http://emj.bmj.com/content/29/3/172.abstract AB