Friedl, A. E. (2001). Teaching science to children: An inquiry approach (5th ed.). McGraw-Hill.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रFriedl, Alfred E. Teaching Science to Children: An Inquiry Approach. 5th ed. Boston: McGraw-Hill, 2001.
एमएलए (9वां संस्करण) प्रशस्ति पत्रFriedl, Alfred E. Teaching Science to Children: An Inquiry Approach. 5th ed. McGraw-Hill, 2001.
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