1 Department of Cardiology, Heart Center, Medical Library, Academic Medical Center, Amsterdam, The Netherlands.
2 Centre for Heart Rhythm Disorders (CHRD), South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide, Royal Adelaide Hospital, Adelaide, Australia.
3 Department of Cardiology, Heart Center, Medical Library, Academic Medical Center, Amsterdam, The Netherlands. Electronic address: j.r.degroot@amc.uva.nl.