1. CERSA Centre of Earth Resources, now the CERSA Luminescence Laboratory, School of Earth and Environmental Sciences, University of St Andrews.
2. Natural England, 2013. National Character Area Profile: 2. Northumberland Sandstone Hills [online]. https://www.gov.uk/government/publications/national-character-area-profiles-data-for-local-decision-making/national-character-area-profiles [accessed 28 January 2019].
3. Natural England, 2015. National Character Area Profile: 12. Mid Northumberland [online]. https://www.gov.uk/government/publications/national-character-area-profiles-data-for-local-decision-making/national-character-area-profiles [accessed 28 January 2019].
4. NHER Northumberland Historic Environment Record. Northumberland County Council, Morpeth. https://www.northumberland.gov.uk, 10417, 10504, 17587-90, 17593. See Williams 2008.