1. CJM 2013 (vol 66 pp. 596)
 Eilers, Søren; Restorff, Gunnar; Ruiz, Efren

The Ordered $K$theory of a Full Extension
Let $\mathfrak{A}$ be a $C^{*}$algebra with real rank zero which has
the stable weak cancellation property. Let $\mathfrak{I}$ be an ideal
of $\mathfrak{A}$ such that $\mathfrak{I}$ is stable and satisfies the
corona factorization property. We prove that
$
0 \to \mathfrak{I} \to \mathfrak{A} \to \mathfrak{A} / \mathfrak{I} \to 0
$
is a full extension if and only if the extension is stenotic and
$K$lexicographic. {As an immediate application, we extend the
classification result for graph $C^*$algebras obtained by Tomforde
and the first named author to the general nonunital case. In
combination with recent results by Katsura, Tomforde, West and the
first author, our result may also be used to give a purely
$K$theoretical description of when an essential extension of two
simple and stable graph $C^*$algebras is again a graph
$C^*$algebra.}
Keywords:classification, extensions, graph algebras Categories:46L80, 46L35, 46L05 

2. CJM 2006 (vol 58 pp. 1268)
 Sims, Aidan

GaugeInvariant Ideals in the $C^*$Algebras of Finitely Aligned HigherRank Graphs
We produce a complete description of the lattice of gaugeinvariant
ideals in $C^*(\Lambda)$ for a finitely aligned $k$graph
$\Lambda$. We provide a condition on $\Lambda$ under which every ideal
is gaugeinvariant. We give conditions on $\Lambda$ under which
$C^*(\Lambda)$ satisfies the hypotheses of the KirchbergPhillips
classification theorem.
Keywords:Graphs as categories, graph algebra, $C^*$algebra Category:46L05 
