Ridley, J. (2002). Safety with machinery. Butterworth- Heinemann.
शिकागो स्टाइल उद्धरणRidley, John. Safety with Machinery. Oxford: Butterworth- Heinemann, 2002.
एमएलए उद्धरणRidley, John. Safety with Machinery. Butterworth- Heinemann, 2002.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.