Complex sentence: From 1951 to 1954, he studied at the "Institut d'études politiques" in Paris, and on his return to Montreal worked for Radio-Canada from 1955 until 1959.
Split into simpler sentences: From 1951 to 1954, he studied at the Institut d'études politiques in Paris. On his return to Montreal worked for Radio-Canada from 1955 until 1959.