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3. Bruner, D. W., P. R.Edwards and A. S.Hopson: Kentucky Agricultural Experiment Station Bull.1949, Nr. 543.
4. Buttiaux, R., etA. Kesteloot: Ann. Inst. Pasteur75, 379 (1948).
5. Edwards, P. R., M. G.West and D. W.Bruner: Kentucky Agricultural Experiment Station Bull.1947, Nr. 499.