1. Buchanan, M. J., Isdale, I. C., and Rose, B. S. (1965). Ann. rheum. Dis., 24, 285.
2. Greenhut, I. J., Silver, R. A., and Campbell, J. A. (1953). Radiology, 60, 257.
3. Lee, F. I., and Loeffler, F. E. (1962). Ibid., 69, 299.
4. Steenstrup, 0. R. (1963). Urinsyrestudier pa normale gravide. Universitetsforlaget, Aarhus.
5. Weragold, A. B. (1960). Obstet. and Gynec., 16, 309.