Choueke, Mark (29 March 2011). Ramboll invests in gifford. London, UK: Gifford.uk.com. Archived from the original on 24 July 2011. Retrieved 6 April 2011.
Choueke, Mark (29 March 2011). Ramboll invests in gifford. London, UK: Gifford.uk.com. Archived from the original on 24 July 2011. Retrieved 6 April 2011.