InProceedings{ALW01,
author={Noga Alon and Alex Lubotzky and
Avi Wigderson},
title={Semi-direct product in groups and
zig-zag product in graphs: connections and
applications},
crossref={FOCS42},
booktitle={Proceedings of the 42nd FOCS},
pages={630-637},
year={2001},
}