Dey, B. (1988). Quality circles: Concepts and practices. Mc Millan Indian.
Dyfyniad Arddull ChicagoDey, B.R. Quality Circles: Concepts and Practices. Delhi: Mc Millan Indian, 1988.
Dyfyniad MLADey, B.R. Quality Circles: Concepts and Practices. Mc Millan Indian, 1988.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.