Title : The Dade group of (almost) extraspecial $p$-groups

Authors : Serge Bouc and Nadia Mazza

Abstract : In this paper, we determine a presentation by explicit generators
and relations for the Dade group of all (almost) extraspecial $p$-groups.
The proof of the main result uses the cohomological properties of the Tits
building corresponding to the natural geometric structure of the lattice of
subgroups of such $p$-groups.