  The Andreev reflection between a normal metal (N) and a heavy-fermion
superconductor (HFS) is studied and the boundary conditions for the electron's
wave function in the two systems are established in the framework of a two band
model for the HFS. Hence we show in a simple and explicit way that the mass
enhancement factors in the heavy-fermion (HF) metal do not cause impedance at
the N/HFS interface, in accordance with arguments previously presented. We also
present an extension of the theory to a two-fluid model for the heavy-fermion,
as possibly applicable to, e.g., CeCoIn_5.
