Enrico Fermi. Collected Papers (Note e Memorie) v. I. Italy 1921 - 1938 (1962). The University of Chicago Press - Accademia Nazionale dei Lincei, Roma.
(translation into Russian) Enrico Fermi. Nauchnye Trudy. I. 1921-1938 Italiya. (pod red. B.Pontecorvo), Nauka, Moskva, 1971.
C. N. Yang, Selected Papers 1945-1980, p. 122-126.
The hypothesis that -mesons may be composite particles formed by the association of a nucleon with an anti-nucleon is discussed. From an extremely crude discussion of the model it appears that such a meson would have in most respects properties similar to those of the meson of the Yukawa theory.
Related references See also K. M. Case, Phys. Rev. 76 (1949) 14;
G. Wentzel, Rev. of Mod. Phys. 19 (1947) 1;