Complex sentence: D'Espagnat obtained his Ph.D. from the Ecole Polytechnique and the Institut Henri Poincaré (Louis de Broglie group), and was a researcher at the Centre National de Recherche Scientifique CNRS, 1947-57.
Split into simpler sentences: D'Espagnat obtained his Ph.D. from the Ecole Polytechnique and the Institut Henri Poincaré (Louis de Broglie group). He was a researcher at the Centre National de Recherche Scientifique CNRS, 1947-57.