1. W. G. Robertson, M. Peacock, and B. E. C. Nor din, in: “Urolithiasis: Physical Aspects,” B. Finlayson, L. L. Hench, L. H. Smith, eds., National Academy of Sciences, Washington, D. C. (1972).
2. W. G. Robertson, M. Peacock, and B. E. C. Nordin, Lancet 2:21 (1969).
3. C. Y. C. Pak, in: “Urolithiasis Research,” H. Fleisch, W. G. Robertson, L. H. Smith, and W. Vahlensieck, ed. Plenum Press, New York-London (1976).
4. B. Carlquist and A. Nelson, Acta. Radiol. 54:305 (1960).
5. A. Catsch, Int. J. Rad. Biol. 4:75 (1961).