Potten, H., & Potten, J. (2001). Clockwise: Elementary classbook [Băng Casset]. Oxford: Oxford University Press.
Dyfyniad Arddull ChicagoPotten, Heather, và Jonathan Potten. Clockwise: Elementary Classbook [Băng Casset]. Oxford: Oxford University Press, 2001.
Dyfyniad MLAPotten, Heather, và Jonathan Potten. Clockwise: Elementary Classbook [Băng Casset]. Oxford: Oxford University Press, 2001.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.