Original sentence: After taking several posts in the United States (at the Research Institute of Advanced Studies in Baltimore, the University of Maryland, Stanford University, UCLA), in 1965 he became a professor at the University of Pennsylvania, where he stayed until his retirement
Edited sentence: After taking several posts in the United States (at the Research Institute of Advanced Studies in Baltimore, the University of Maryland, College Park, Stanford University, UCLA), in 1965 he became a professor at the University of Pennsylvania, where he stayed until his retirement