1. Veldman, A. J. P., and Kaiserling, E., in: The reticuloendothelial system. A comprehensive treatise, vol.1, p. 381. Eds I. Carr and W. T. Daems. Plenum Press, New York 1980.
2. Kendall, M. D., and Frazier, J. A., Cell Tissue Res.199 (1979) 37.
3. Fonfría, J., Barrutia, M. G., Villena, A., and Zapata, A., Cell Tissue Res.225 (1982) 687.
4. Leceta, J., Ph. D. thesis, Complutense University of Madrid, Spain (1984).
5. Plytycz, B., Personal communication.