Spitzweck, Markus, and Paul Arne Østvær. “A Bott Inverted Model for Equivariant Unitary Topological $K$-Theory”. Mathematica Scandinavica 106, no. 2 (June 1, 2010): 211–216. Accessed July 24, 2026. https://journals.msp.org/mscand/article/view/564.