1. Armstrong, E. L., Adams, W. L., Tragerman, L. G. and Townsend, E. W. (1942). Ann. intern. Med., 16, 113.
2. Bates, J. L. (1937). Lancet, 1, 1108.
3. Brunton, T. Lauder (1896). Trans. med. Soc. Lond., 19, 117.
4. Catti, G. (1907). Z. klin. Med., 61, 269.
5. Coombs, C. (1911). Brit. J. Child. Dis., 8, 109.