1. Abdou, N.J., Abdou, N.L.: Bone marrow: the bursa equivalent in man? Science 175, 446–448 (1972).
2. Abramson, H. A.: The influence of a low electromotive force on the electrophoresis of lymphocytes of different ages. J. exp. Med. 41, 445–450 (1925).
3. Absolon, K.G., Rikkers, H., Hagihara, P.: Experimental lymphocytopenia and hypogammaglobulinemia production. Surg. Forum 15, 149–150 (1964).
4. Ackerman, G.A.: Cytochemistry of the lymphocytes. In: Rebuck, J.W. (Ed.): The Lymphocyte and Lymphocytic Tissue, p. 28–53. New York: Hoeber 1960.
5. Ackerman, G.A.: Electron microscopy of the bursa of Fabricius of the embryonic chick with parti cular reference to the lympho-epithelial nodules. J. Cell Biol. 13, 127 —146 (1962).