About the quark currents in leptonic decaies of pseudoscalar mesons
  With usage of obvious mechanisms of quark currents the amplitudes of leptonic decaies of pseudoscalar mesons are investigated. The estimation for a constant of leptonic decay of the D+ meson is obtained, f_D+ ~ 0.23 GeV. 
V. P. Efrosinin, A. N. Khotyantsev