Electrically tunable diffraction of light from 2D nematic colloidal crystals M. Humar, M. Škarabot, M. Ravnik, S. Žumer, I. Poberaj, D. Babič and I. Muševič Eur. Phys. J. E, 27 1 (2008) 73-79 Published online: 25 July 2008 DOI: 10.1140/epje/i2008-10353-0