1. Proc. 2nd Intern. Conf. on Polarized targets;Scheffler,1972
2. Dynamic proton polarization in ammonia
3. W. de Boer, unpublished work at CERN (1971).
4. K. Guckelsberger, unpublished work at CERN (1974).
5. Report of the Workshop on polarized target materials;Hill,1978