Andersen, Niels Byrial. “Invariant Fundamental Solutions and Solvability for $\mathrm{GL} (n, \mathsf{C}) U(p,q)$”. Mathematica Scandinavica 86, no. 1 (March 1, 2000): 143–160. Accessed July 24, 2026. https://journals.msp.org/mscand/article/view/919.