This publication was made possible through a bequest from my beloved late wife. United together in this present collection are those works by the author which have not previously appeared in book form. The following are excepted: Vorlesungen über Differential und Integralrechnung (Lectures on Differential and Integral Calculus) Vols 1-3, Birkhäuser Verlag, Basel (1965-1968); Aufgabensammlung zur Infinitesimalrechnung (Exercises in Infinitesimal Calculus) Vols I, 2a, 2b, and 3, Birkhäuser Verlag ...