Complex sentence: In 1900, Dehio started the "Handbuch der deutschen Kunstgeschichte" (Handbook of German Art History); this project is still alive, managed by the'Dehio-Vereinigung', Munich.
Split into simpler sentences: In 1900, Dehio started the "Handbuch der deutschen Kunstgeschichte" (Handbook of German Art History). The project is ongoing and managed by the'Dehio-Vereinigung', Munich.