References
- Popert, A. J., Meijers, K. A. E., Sharp, J. & Bier, F.: Ann. rheum. Dis., 20, 18, 1961.
- Hamilton, E. B. D. & Scott, J. T.: Arth. & Rheum., 5, 502, 1962.
- Research Sub-Committee of the Empire Rheumatism Council: Ann. rheum. Dis., 20, 315, 1961.