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2. J.S.Fruton in “Advances in Protein Chemistry” Vol.V,1949;
3. M.Goodman and G.W.Kenner,ibid.,Vol.XII,1957;
4. K.Hofmann and P.G.Katsoyannis,in “The Proteins” Vol.1,ed.H.Neurath,Academic Press,New York,1963;
5. R.Boissonnas,in “Advanes in Organic Chemistry”,Vol.3,ed.R.A.Raphael,Interscience,New York,1963;