Invariant fundamental solutions and solvability for $\mathrm{GL} (n, \mathsf{C})/U(p,q)$.

Andersen, N. B. (2000). Invariant fundamental solutions and solvability for $\mathrm{GL} (n, \mathsf{C})/U(p,q)$. MATHEMATICA SCANDINAVICA, 86(1), 143–160. https://doi.org/10.7146/math.scand.a-14286