The Music Library just received McCorkle's thematic catalogue of Robert Schumann's works. This invaluable reference tool was published by G. Henle, and the text is predominantly in German. It also has a helpful English translation of the Foreword and other introductory material.
McCorkle, Margit L. Robert Schumann: Thematisches-Bibliographisches Werkverzeichnis. München: G. Henle, 2003. Call no.: MUR ML134.S4 A28 2003b