See William Roberts, Memories of the War to End War 1914-18 (London, 1974) for an account of life on the front line and the commissioning processes for war artists.
Athletes Exercising in a Gymnasium, The Wedding, The Auction Room and The Cockneys — see 'William Roberts: Catalogue raisonné' available at http://www.englishcubist.co.uk/catchron.html.
For a full account of Vorticism see the introductory essay by Richard Cork in the exhibition catalogue Vorticism and Its Allies (London: Arts Council of Great Britain, 1974), pp. 5-26. A recent and concise definition is available at the Tateʼs website: https://www.tate.org.uk/art/art-terms/v/vorticism.