1. M.A. Ruderman and C.Kittel, Phys. Rev.96, 99 (1954)
2. T.Kasuya, Prog.Theoret. Phys. (Kyoto) 16, 45 (1956)
3. K.Yosida, Phys. Rev. 106, 893 (1957)
4. Y.Yafet, Phys. Rev. B36 3948 (1987)
5. C.Kittel in “Indirect Exchange Interactions in Metal” Solid State Physics, Vol 22, pag.l (Academic Press, N.Y.I972). This is an extraordinary well writen and pedagogical paper. TheApendix A deals with the long range exchange interaction in 1-D infinite systems, but the result in it is incorrect. The correct one is the same minus Π/2 as was proven by Yafet in ref.4