Complex sentence: Dealers were appointed in Germany for this purpose and Theodore Fischer was instructed to hold an auction of degenerate art in Switzerland which took place on 30 June 1939 at the Grand Hotel National.
Split into simpler sentences: Dealers were appointed in Germany for this purpose and Theodore Fischer was instructed to hold an auction of "degenerate art" in Switzerland. This took place on 30 June 1939 at the Grand Hotel National.