1. Mintz, B., Science, 1967,158, 1484.
2. Phillips, S.M., Martin, W.J., Shaw, A.R., and Wegmann, T.G.,Nature, 1971,234, 146.
3. Wegmann, T.G., Hellstrom, P. and Hellstrom, K.E., Proc. Nat. Acad. Sci. U.S.A.,1971,68, 1644.
4. Barnes, R.D., and Tuffrey, M., Microenvironment Aspects of Immunity (B.D. Jankovic and K. Isakovic Eds.) Plenum Pub. Corp. N.Y., 1972, 427.
5. Barnes, R.D., and Tuffrey, M., Scand. J. Immunol. 1972, 1, 284.