Also, would recommend William Klein 2 volume set of postmarks of Austria 1867, 1883 and 1890. Dr Edwin Mueller also wrote a Handbook of Abstempelmarken (cancels) of Austria and Lombardy Venetia (1925). This last volume covers issues of 1850, 1858 1861, 1863. Both of these publications are in German. The Klein book has a separately published English version of just introduction of 36 pages that is very helpful. You can probably find this for sale occasionally, or on loan from the American Philatelic Research Library in Bellefonte. That said, the German is not hard to grasp after you have worked with the material a while.