National Indicators of Public Investment in Education. US Department of Education.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNational Indicators of Public Investment in Education. US Department of Education.
एमएलए (9वां संस्करण) प्रशस्ति पत्रNational Indicators of Public Investment in Education. US Department of Education.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.