Fraknoi, Andrew. "Introduction to the Solar System - Sample Syllabus". OER Commons. Institute for the Study of Knowledge Management in Education, 06 Jan. 2017. Web. 18 Feb. 2019. <https://www.oercommons.org/authoring/19408-introduction-to-the-solar-system-sample-syllabus>.
Fraknoi, A. (2017, January 06). Introduction to the Solar System - Sample Syllabus. OER Commons. Retrieved February 18, 2019, from https://www.oercommons.org/authoring/19408-introduction-to-the-solar-system-sample-syllabus.