Wallwork, K. L. (March 1956). "Subsidence in the Mid-Cheshire Industrial Area". The Geographical Journal. 122 (1): 40–45. doi:10.2307/1791474. JSTOR1791474.
Wallwork, K. L. (March 1956). "Subsidence in the Mid-Cheshire Industrial Area". The Geographical Journal. 122 (1): 40–45. doi:10.2307/1791474. JSTOR1791474.