1Committee on a Conceptual Framework for the New K-12 Science Education Standards, National Research Council. A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas [EB/OL]. http:// www.nap.edu/catalog.php?record_id= 13165, 2011-07-20.
2Richard A. Duschl, Heidi A. Schweingruber & Andrew W. Shouse; Committee on Science Learning, Kindergarten through Eighth Grade; National Research Council. Taking Science to School: Learning and Teaching Science in Grades K-8 [M]. Washington, DC: National Academies Press, 2007: 137.
