Nelly van Doesburg or Cupera, Pétro van Doesburg, Nelly van Moorsel (July 27, 1899 – October 1, 1975) was a Dutch avant-garde (dada) musician, dancer and artist. As a painter, she used the Pseudonym Cupera.Doesburg was born Nelly van Moorsel on July 27, 1899 in The Hague. Her field of work included dadaism. She married Theo van Doesburg after moving to Paris with him in 1923. She was his third wife.She died on October 1, 1975 in Meudon.