Reconstruction of the electron-phonon interaction function in Ta,   2H-NbSe2 and MgB2 from spectra of S - c - N point-contacts
  Using Ta, 2H-NbSe2 and MgB2 as an example it is shown that it is possible to reconstruct qualitatively a function of the electron-phonon interaction from point-contact spectra in a superconducting state. The limits and the restrictions of this method are also shown. The results obtained are compared with available literature data. 
N. L. Bobrov, V. V. Fisun, O. E. Kvitnitskaya, V. N. Chernobay, and I.   K. Yanson
cond-mat.supr-con