Koba, S., & Mitchell, C. T. (2011). Hard-to-teach science concepts: A framework to support learners, grades 3-5. National Science Teachers Association.
芝加哥风格引文Koba, Susan, 与 Carol T. Mitchell. Hard-to-teach Science Concepts: A Framework to Support Learners, Grades 3-5. Arlington, Va.: National Science Teachers Association, 2011.
MLA引文Koba, Susan, 与 Carol T. Mitchell. Hard-to-teach Science Concepts: A Framework to Support Learners, Grades 3-5. National Science Teachers Association, 2011.
警告：这些引文格式不一定是100％准确.