Complex sentence: After serving in the Luftwaffe in World War II, he took degrees at the universities of Marburg and Köln, then moved to the United States to study for a Ph.D. at New York University.
Split into simpler sentences: After serving in the Luftwaffe in World War II, he took degrees at the universities of Marburg and Köln. He then moved to the United States to study for a Ph.D. at New York University.