1. See e.g.: Mesons in Nuclei, Rho, M., Wilkinson, D.H. (eds.), Vol. II. Amsterdam: North Holland 1979
2. Arenh�vel, H.: Proc. Workshop ?From Collective States to Quarks in Nuclei?, Arenh�vel, H., Saruis, A.M. (eds.), Lecture Notes in Physics, Vol. 137, p. 136. Berlin-Heidelberg-New York: Springer 1981
3. Arenh�vel, H.: Proc. Workshop ?Intermediate Energy Nuclear Physics with Monochromatic and Polarized Photons?, Matone, G., Stipcich, S. (eds.), Frascati 1980
4. de Forest, T., Walecka, J.D.: Adv. Phys.15, 1 (1966)
5. Partovi, F.: Ann. Phys.27, 79 (1964)