Simms, Frederick Walter (1844). Practical Tunneling. London: Troughton and Simms. Retrieved 17 September 2009. Full text at Internet Archive (archive.org)
Broome, D.C (1963). "The development of the modern asphalt road". The Surveyor and Municipal and County Engineer. 122 (3278 & 3279). London: 1437–1440, 1472–1475. – Snippet view: Simms & Claridge p.1439