There is a lot of work because the author's purpose is to create a photo collection to donate it to the famous Saxon State and University Library Dresden
, one of the largest and best endowed academic libraries in Germany. At the Saxon State and University Library, there are many online compilations of photographic and cartographical works. This would be the right place for any aerial photo taken during the Trolley Mission. Looking for aerial photos, recognizing and identifying them, and analyzing the flight routes is no commercial work - it's an academic study. Therefore, the existing books and e-books are sold without any profit margin.