During the 1940s Surrealism's influence was also felt in England, America and the Netherlands where Gertrude Pape and her husband Theo van Baaren helped to popularize it in their publication The Clean Handkerchief. Mark Rothko took an interest in biomorphic figures, and in England Henry Moore, Lucian Freud, Francis Bacon and Paul Nash used or experimented with Surrealist techniques. However, Conroy Maddox, one of the first British Surrealists whose work in this genre dated from 1935, remained within the movement, and organized an exhibition of current Surrealist work in 1978 in response to an earlier show which infuriated him because it did not properly represent Surrealism. Maddox's exhibition, titled Surrealism Unlimited, was held in Paris and attracted international attention. He held his last one-man show in 2002, and died three years later. Magritte's work became more realistic in its depiction of actual objects, while maintaining the element of juxtaposition, such as in 1951's Personal Values (Les Valeurs Personnelles) and 1954's Empire of Light (L’Empire des lumières). Magritte continued to produce works which have entered artistic vocabulary, such as Castle in the Pyrenees (Le Château des Pyrénées), which refers back to Voix from 1931, in its suspension over a landscape.