Bird, J., Newby, B., & Timings, R. (1996). Engineering GNVQ: Intermediate. Butterworth-Heinemann.
Dyfyniad Arddull ChicagoBird, John, Bruce Newby, and Roger Timings. Engineering GNVQ: Intermediate. Oxford: Butterworth-Heinemann, 1996.
Dyfyniad MLABird, John, et al. Engineering GNVQ: Intermediate. Butterworth-Heinemann, 1996.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.