Article in journal: Guigueno, Vincent (2005). ‘Engineering the Words: Robert Louis Stevenson and the Bell Rock Lighthouse’. The Yale University Library Gazette, Vol.80, No. 1/2: p.57-64.
JSTOR: https://www.jstor.org/stable/40859686
Book: Dobson, E. (1850). A Rudimentary Treatise on Foundations and Concrete Works: Containing a Synopsis of the Principal Cases of Foundation Works. London: J. Weale, p.7.