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2. Warburg, 0.: The Metabolism of Tumors, American edition, translated by F. Dickens, New York, 1931, Richard C. Smith, Inc. , p. 79.
3. Hawk, P.E., Oser, B.L., and Summerson, W.H.: Practical Physiological Chemistry, ed. 12, New York, 1951, The Blakiston Company , p. 297.
4. Nitrogen Content of Dental Pulp