Kania, Nia, et al. “Constructing and Providing Content Validity Evidence through the Aiken’s V Index Based on the experts’ Judgments of the Instrument to Measure Mathematical Problem-Solving Skills”. REID (Research and Evaluation in Education), vol. 10, no. 1, June 2024, pp. 64-79, doi:10.21831/reid.v10i1.71032.