%0 conference lecture %@ %A Havermeyer, F., Rupp, R.A., Schubert, D.W., Kraetzig, E. %D 1999 %J 2nd European Conference on Neutron Scattering, ECNS 99, Session C 04 %P 95 %T Neutron diffraction from holographic gratings in PMMA %U %X