1. Aird, J., 1971. Immunology 20: 617.
2. Allison, A. C., and Davies, A. J. S., 1971. Nature (Loud.) 233: 330
3. Allison, A. C., Denman, A. M., and Barnes, R. D., 1971.
4. Andersson, B., and Blomgren, H., 1971. Cell. Immunol. 2: 411.
5. Andersson, J., Möller, G., and Sjöberg, O., 1972. Cell. Immunol. 4: 381.