1. J. Ball (1969 ): "Early Synovectomy in Rheumatoid Arthritis ." Excerpta Medica Foundation, Amsterdam, p.22 .
2. E. Gardner (1966 ): Arthritis and Allied Conditions , 7th Edition . Philadelphia: Lea and Febiger, p.51 .
3. W. Hymans, W. D. Paul, and H. Herschel (1969 ): "Early Synovectomy in Rheumatoid Arthritis ."Excerpta Medica Foundation, pp.69 , 69 .