Complex sentence: Only the 88 works above have been assigned opus numbers, the remaining works by Richard Strauss have been catalogued by Erich Herrmann Mueller von Asow (1892--1964) in 1959.
Split into simpler sentences: Only the 88 works above have been assigned opus numbers. The remaining works by Richard Strauss were catalogued by Erich Herrmann Mueller von Asow (1892--1964) in 1959.