Gjerde, Richard, and Ørjan Johansen. “$C^*$-Algebras Associated to Non-Homogeneous Minimal Systems and Their K-Theory”. Mathematica Scandinavica 85, no. 1 (September 1, 1999): 87–104. Accessed July 24, 2026. https://journals.msp.org/mscand/article/view/941.