1. Garcia, A. M., Acta Histochem., 17, 230 (1964).
2. Alpen, E. L., and Johnston, M. E., Proc. Ninth Congr. Europ. Soc. Haematol., Lisbon, 1963, 1507 (S. Karger, Basel/New York, 1963).
3. Alpen, E. L., J. Sci. Instrum., 43, 493 (1966).
4. Pollister, A. W., and Ornstein, L., Analytical Cytology, edit. by Mellors, R. C., 1 (3) (Blakiston, New York, 1955).
5. Ornstein, L., Lab. Invest., 1, 250 (1952).