1. Wells, H. J. American Medical Association 81, Page 1017, 1923.
2. Strong, L. American Naturalist 60, Page 201, 1926.
3. Boveri, T., The Origin of Malignant Tumors (M. Boveri, trans.) Williams and Wilkins, Baltimore, Page 34, 1929.
4. Burdette, W., Cancer Research 15, Page 201, 1955.
5. Miller, E. and Miller, J., The Chemical Mutagens: Principles and Methods for Their Detection, Vol. I, A. Hollaender, Editor. Plenum Press, New York, Page 83, 1971.