RT Journal Article SR Electronic T1 Advance healthcare directives JF Clinical Medicine JO Clin Med FD Royal College of Physicians SP 231 OP 233 DO 10.7861/clinmedicine.6-3-231 VO 6 IS 3 A1 Raymond Hoffenberg YR 2006 UL http://www.rcpjournals.org/content/6/3/231.abstract AB