Complex sentence: World Institute for Development Economics Research of the United Nations University or (UNU-WIDER) is a development economics research institute, founded 1984 in Helsinki, it was the first research and training centre of the United Nations University (UNU).
Split into simpler sentences: World Institute for Development Economics Research of the United Nations University (UNU-WIDER) is a development economics research institute, founded in Helsinki in 1984. It was the first research and training centre of United Nations University (UNU).