Neutron--Antineutron Oscillations at the Surface of Nuclei
  We discuss some aspects of possible neutron--antineutron oscillations in nuclei. The phenomenon occurs mostly at the surface of nuclei, and hence {\sl i)} is not very sensitive to medium corrections and {\sl ii)} makes use of the antinucleon-nucleus interaction in a region probed by experiments at CERN. 
C.B. Dover, A. Gal and J.M. Richard