McDonald, Madi. "The Periodic Table- The Beginning". OER Commons. Institute for the Study of Knowledge Management in Education, 10 May 2018. Web. 22 Nov. 2024. <https://oercommons.org/authoring/28657-the-periodic-table-the-beginning>.
McDonald, M. (2018, May 10). The Periodic Table- The Beginning. OER Commons. Retrieved November 22, 2024, from https://oercommons.org/authoring/28657-the-periodic-table-the-beginning.