RIVEROS, Hector Gerardo. How to Find Pre-Concepts about Charges and Magnets?. European Journal of Physics Education, [S.l.], v. 11, n. 2, p. 1-4, jan. 2020. ISSN 1309-7202. Available at: <http://eu-journal.org/index.php/EJPE/article/view/260>. Date accessed: 26 may 2020.