1. Akert, K., Moor, H., Pfenninger, K., Sandri, C.: Contribution of new impregnation methods and freeze etching to the problem of synaptic fine structure. In: Progress in brain research, vol. 31, p. 223?240, ed. by K. Akert and P. G. Waser. Amsterdam-London-New York: Elsevier 1969b.
2. ?? Pfenninger, K.: Synaptic fine structure and neural dynamics. In: Cellular dynamics of the neuron, vol. 8, p. 245?260. ed. by S. H. Barondes. New York: Academic Press 1969a.
3. ?? Sandri, C.: Identification of the active synaptic region by means of histochemical and freeze etching techniques. In: Excitatory synaptic mechanisms, p. 27?41, ed. by P. Andersen and J. K. S. Jansen. Oslo: Universitetsforlaget 1970.
4. Andres, K. H.: Micropinozytose im Zentralnervensystem. Z. Zellforsch.64, 63?73 (1964).
5. Bennett, M. V. L., Nakajima, Y., Pappas, G. D.: Physiology and ultrastructure of electronic junctions. J. Neurophysiol.30, 161?300 (1967).