M.F. Laranjeira, An elementary theory of thermal and pressure diffusion in gaseous binary and complex mixtures I. General theory, Physica 26, 409-416 (1960)
H.A. Tasman, A.J.H. Boerboom and H. Wachsmuth, Calculation of the ion optical properties of inhomogeneous magnetic sector fields Part 3: Oblique incidence and excit at curved boundaries, Z. Naturforsch. Teil A 14, 822-827 (1959)
H.A. Tasman and A.J.H. Boerboom, Calculation of the ion optical properties of inhomogeneous magnetic sector fields, including the second order aberrations in the median plane, Z. Naturforsch. Teil A 14, 121-129 (1959)
