Literature

Ben Nicholson, exh. cat., Galerie Charles Lienhard, 1959, cat. no. 43, pp. 24 and 27 (illus.) (illustration wrongly numbered as cat. 35, 'Sept 56 (Siena Cathedral)')
John Russell, Ben Nicholson: drawings, paintings and reliefs 1911-1968, Thames & Hudson, 1969, fig. 59 (illus.) (wrongly listed as 'September 1956 (Siena cathedral)')
Charles Harrison, Ben Nicholson, exh. cat., Tate Gallery, 1969, cat. no. 88, pp. 51 and 70 (col. illus.) (wrongly listed as 'September 1956 (Siena cathedral)')
Jeremy Lewison, Ben Nicholson, exh. cat., Tate Gallery, 1993, cat. no. 109, pp. 184 and 231 (col. illus.) (wrongly listed as 'September 1956 (Siena Campanile)')
Norbert Lynton, Ben Nicholson, Phaidon, 1993, p. 300, pl. 284 (illus.) (listed as '1957, May (Siena campanile)')
Peter Khoroche, Ben Nicholson: drawings and painted reliefs, Lund Humphries, 2002, fig. 60, pp. 77 and 120 (col. illus.) 
Peter Khoroche, Ben Nicholson: 'chasing out something alive': drawings and painted reliefs 1950-1975, exh. cat., Kettle's Yard, 2002, cat. no. 15, pp. 42 and 45 (col. illus.)