By BBC
By Gerngross, Gunter, Puchta, Herbert
By Rixon, Shelagh
By Hess, Natalie
By Scottish Primary Mathematics Group
By McNicholas, Jim
By Gartside, L., Taylor, Shirley
By Raghallaigh, Denise Ní, Neill, Úna Ní, Fhoghlú, Caitlín Ní
By Berry, Martyn
By Masters, Anthony
By Scott, Forrest S., etc.
By Lynch, Emma
By Hawes, Alison
By Thompson, Paul
By Nicholls, Derek, Speakman, Ray
By Lawrence, D. H., Reeves, James
By Driving Standards Agency
By Jensen, Julie M.
By Gosse, Edmund
By Vassanji, M.G.
By Hartnett, Anthony, Naish, Michael
By Loveday, George
By Butler, John E.
By Harrap
By Philip Burnard, Paul Gill (University College London, UK)