Search for lepton flavour violation in ep collisions at HERA A. Aktas, C. Alexa, V. Andreev, T. Anthonis, B. Antunovic, S. Aplin, A. Asmone, A. Astvatsatourov, A. Babaev, S. Backovic et al. (284 more) Eur. Phys. J. C, 52 4 (2007) 833-847 Published online: 24 October 2007 DOI: 10.1140/epjc/s10052-007-0440-2