Knöchelmann, N., S. Krueger, A. Flack, and C. Osterhaus. “Adults’ Ability to Interpret Covariation Data Presented in Bar Graphs Depends on the Context of the Problem”. Frontline Learning Research, vol. 7, no. 4, Dec. 2019, pp. 58 -65, doi:10.14786/flr.v7i4.471.