1. Stuart, K.L. : In Diseases of Children in the Subtropics and the Tropics, D. B. Jelliffe, Ed. London, Edward Arnold, 1970, p. 485.
2. Gopalan, G.C.: In Diseases of Children in the Subtropics and the Tropics, D. B. Jelliffe, Ed. London, Edward Arnold, 1970, p. 480.