Authors: Fenglian Xu; Elizabeth A Sullivan; Richard C Madden; Deborah Black; Lisa R Jackson Pulver Journal: BMC Med Res Methodol Date: 2012-01-30 Impact factor: 4.615
Authors: Geoffrey V Gill; Aziz A Ismail; Nicholas J Beeching; Sarah B J Macfarlane; Mark A Bellis Journal: J R Soc Med Date: 2003-07 Impact factor: 18.000