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Dyfyniad Arddull ChicagoCresswell, John W. Research Design: Pendekatan Kualitatif, Kuantitatif, Dan Mixed. Pustaka Pelajar, 2015.
Dyfyniad MLACresswell, John W. Research Design: Pendekatan Kualitatif, Kuantitatif, Dan Mixed. Pustaka Pelajar, 2015.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.