Ultracold electron source for single-shot diffraction studiesG. Taban, M. P. Reijnders, B. Fleskens, S. B. van der Geer, O. J. Luiten and E. J. D. VredenbregtEPL, 91 4 (2010) 46004DOI: https://doi.org/10.1209/0295-5075/91/46004