Atkinson, M., Hardwicke Drummond Rawnsley, 1851-1920, M.Phil. thesis (Lancaster University, 1993) (view full text)

McGaffey, B. A. K., Three Founders of the British Conservation Movement, 1865-1895: Sir Robert Hunter, Octavia Hill, and Hardwicke Drummond Rawnsley, Ph.D. dissertation (Texas Christian University, 1978)