Complex sentence: Barton J. Bernstein (born 1936) is Professor of History at Stanford University and Co-Chair of the International Relations Program and the International Policy Studies Program, having received his Ph.D. in history from Harvard University.
Split into simpler sentences: Barton J. Bernstein (born 1936) is Professor of History at Stanford University and Co-Chair of the International Relations Program and the International Policy Studies Program. He received his Ph.D. in history from Harvard University.