The Poisson equation in homogeneous Sobolev spaces. - Tatiana Samrowski; Werner Varnhorn (Int. J. Math. Math. Sci., 2004)

Error estimates for approximate approximations with Gaussian kernels on compact intervals. - Frank Müller 008; Werner Varnhorn (J. Approx. Theory, 2007)

On approximation and numerical solution of Fredholm integral equations of second kind using quasi-interpolation. - Frank Müller 008; Werner Varnhorn (Appl. Math. Comput., 2011)