https://historicengland.org.uk/advice/find/a-z-publications/
https://www.durham.gov.uk/media/22749/Standards-for-Archaeological-Work-in-County-Durham-and-Darlington/pdf
https://www.york.gov.uk/downloads/file/17090/regional_statement_of_good_practice
https://www.durham.gov.uk/article/2013/NE-Research-Framework-for-the-Historic-Environment
www.layersoflondon.org/map
http://www.locatinglondon.org/index.html
http://bombsight.org/#15/51.5050/-0.0900
https://maps.nls.uk/os/
https://www.old-maps.co.uk/#/