M. V. Pedyash, D. K. Petrov, Ya. G. Ponomarev, and H.T. Rakhimov, Influence of finite lifetime of quasi-particles on the I(V) characteristics of break junctions based on high-T_c superconductors, Low Temp. Phys. 18, (1992) [Fiz. Nizk. Temp. 18, 606-608, (1992)].