sentences:  Their angular artworks contrasted with the more rounded styles of their seniors, Henry Moore and Barbara Hepworth, and they were dubbed by art critic Herbert Read as the "Geometry of Fear".He held his first solo exhibition at Gimpel Fils in 1957, with four more in the decade to 1967.He also exhibited at the São Paulo Biennale in 1957, Documenta 2 in Kassel in 1959, and the 1964 Venice Biennale.