1. De Rujula, A., Georgi, H., Glashow, S.L.: Phys. Rev. D12, 147 (1975)
2. Gromes, D., Stamatescu, I.O.: Nucl. Phys. B112, 213 (1976)
3. Gromes, D.: Nucl. Phys. B130, 18 (1977)
4. Gromes, D.: The quark structure of matter. Isgur, N., Karl, G., O'Donnell, P.J. (eds.), pp. 1?56. Singapore: World Scientific 1985
5. Gromes, D.: Z. Phys. C ? Particles and Fields11, 147 (1981)