Complex sentence: A sphinx from Hattusa, taken for restoration out of Turkey to Germany in 1917 and not returned still, was recently at the center of a Turkish move towards applying restrictions on German archaeologists working in the country.
Split into simpler sentences: A sphinx from Hattusa was taken for restoration out of Turkey to Germany in 1917 and has not been returned. It was recently at the center of a Turkish move to apply restrictions on German archaeologists working in the country.