1. Brattain, M. G., Strobel-Stevens, J., Fine, D., Webb, M., and Sariff, A., 1980, Establishment of mouse colon carcinoma cell lines with different metastatic properties Cancer Research, 40, 2142?2146.
2. Caputo, M., Corsi, A., Sacchi, A., and Zupi, G., 1980, Drug response of two different in vitro tumor lines derived from lung metastases of 3LL. Metastasis: Clinical and Experimental Aspects, edited by K. Hellmann, P. Hilgard and S. Eccles (The Hague: Martinus Nijhoff), pp. 406?410.
3. Chambers, A. F., Hill, R. P., and Ling, V., 1981, Tumor heterogeneity and stability of the metastatic phenotype of mouse KHT sarcoma cells. Cancer Research, 41, 1368?1372.
4. Cheu, T. R., 1977, In situ detection of mycoplasma contamination in cell cultures by fluorescent Hoechst 33258 stain. Experimental Cell Research, 104, 255?262.
5. Chow, D. A., and Greenberg, A. H., 1980, The generation of tumor heterogeneity in vivo. International Journal of Cancer, 25, 261?265.