1. Astaldi, G. and Lisiewicz, J., Lymphocytes. Structure, Production, Functions. Edelson, Naples. 1971.
2. Ben-Ishay, Z. and Yoffey, J. M., Irs. J. Med. Sci. 7 (1971) 948.
3. Balckett, N. M., J. Natl. Cane. Inst. 41 (1968) 908.
4. Campbell, F. R., Am. J. Anat. 135 (1972) 521.
5. Catavsky, D., Scand. J. Haemat. 19 (1977) 211.