Complex sentence: He received his PhD in International Relations from the Institute of USA and Canada in Moscow in 1988, then worked in the newly created Institute of Europe in Moscow until 1992, when he moved to Oslo, Norway and joined PRIO.
Split into simpler sentences: He received his PhD in International Relations from the Institute of USA and Canada in Moscow in 1988, then worked in the Institute of Europe in Moscow until 1992. In 1992 he moved to Oslo, Norway and joined PRIO.