Smith, Geoffrey (2001). "It's green not grim up North". The Garden. Royal Horticultural Society. Archived from the original on 1 December 2008. Retrieved 20 March 2008.
"GWG Awards". Garden Writers Guild. 2006. Archived from the original on 24 March 2008. Retrieved 20 March 2008.
Smith, Geoffrey (2001). "It's green not grim up North". The Garden. Royal Horticultural Society. Archived from the original on 1 December 2008. Retrieved 20 March 2008.