1. Article in Journal: Harris, E. (May 1968), “‘Vitruvius Britannicus’ before Colen Campbell”, The Burlington Magazine, vol. 998, pp: 338+340-343+345-346
2. PhD Thesis: O’Hara, J. (2010), ‘Colen Campbell and the Preparatory Drawings for Vitruvius Britannicus’, University of York pp. 1-442