\bibitem{Venkataramanan02}   L.~Venkataramanan, Y.-Q.~Song, M.D.~Hurlimann,
                             {\it Solving Fredholm Integrals of the First Kind with Tensor Product Structure in 2 and 2.5 Dimensions},
                             IEEE Trans. Signal Proc. {\bf 50} (5), 1017, 2002.