Authors: Vinjar Fønnebø; Sameline Grimsgaard; Harald Walach; Cheryl Ritenbaugh; Arne Johan Norheim; Hugh MacPherson; George Lewith; Laila Launsø; Mary Koithan; Torkel Falkenberg; Heather Boon; Mikel Aickin Journal: BMC Med Res Methodol Date: 2007-02-11 Impact factor: 4.615