Freivalds, A. (2014). Niebel's methods, standards, and work design 13th ed / Andris Freivalds dan Benjamin W. Niebel. Mc Graw-Hill.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रFreivalds, Andris. Niebel's Methods, Standards, and Work Design 13th Ed / Andris Freivalds Dan Benjamin W. Niebel. Mc Graw-Hill, 2014.
एमएलए (8वां संस्करण) प्रशस्ति पत्रFreivalds, Andris. Niebel's Methods, Standards, and Work Design 13th Ed / Andris Freivalds Dan Benjamin W. Niebel. Mc Graw-Hill, 2014.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.