"Deng". On-line Welsh Grammar Guide. University of Wales, Lampeter. Retrieved 30 July 2009. [dead link]
"Deng". On-line Welsh Grammar Guide. University of Wales, Lampeter. Retrieved 30 July 2009. [dead link],"Pump". On-line Welsh Grammar Guide. University of Wales, Lampeter. Retrieved 30 July 2009. [dead link]