The following journal articles and books are useful if you want to learn more about the systematic reviews.

Systematic Review Series: Annals of Internal Medicine

1. Cook DJ ; Mulrow CD ; Haynes RB. Systematic reviews: synthesis of best evidence for clinical decisions Ann Intern Med 1997 Mar 1; 126(5):376-80.
2. Mulrow CD ; Cook DJ ; Davidoff F. Systematic reviews: critical links in the great chain of evidence. Ann Intern Med 1997 Mar 1; 126(5):389-91.
3. Hunt DL ; McKibbon KA. Locating and appraising systematic reviews. Ann Intern Med 1997 Apr 1; 126(7):532-8.
4. McQuay HJ ; Moore RA. Using numerical results from systematic reviews in clinical practice. Ann Intern Med 1997 May 1; 126(9):712-20.
5. Bero, LA ; Jadad, AR. How consumers and policymakers can use systematic reviews for decision making. Ann Intern Med 1997 July 1; 127(1): 37-42.
6. Lau J, Ioannidis JP, Schmid CH. Quantitative synthesis in systematic reviews. Ann Intern Med 1997 Nov 1; 127(9): 820-826.
7. Mulrow C, Langhorne P, Grimshaw J. Integrating heterogeneous pieces of evidence in systematic reviews. Ann Intern Med 1997 Dec 1; 127(11): 989-995.