1. Surveillance Epidemiology and End Results [website]. Available from: http://seer.cancer.gov/statfacts/more.html [accessed 01.01.14].
2. Lupus Research Institute [website]. Available from: http://www.lupusresearchinstitute.org/lupus-facts/lupus-fact-sheet [accessed 01.01.14].
3. The risk of lymphoma development in autoimmune diseases: a meta-analysis;Zintzaras;Arch Intern Med,2005
4. The Newcastle-Ottawa Scale (NOS) for assessing the quality of non-randomised studies in meta-analyses [website]. Available from: http://www.ohri.ca/programs/clinical_epidemiology/oxford.asp [accessed 01.01.14].
5. Meta-analysis in clinical trials;DerSimonian;Control Clin Trials,1986