PORTER, T.; CATALÁN MOLINA, D.; BLACKWELL, L.; ROBERTS, S.; QUIRK, A.; LEE DUCKWORTH, A.; TRZESNIEWSKI, K. Measuring Mastery Behaviors at Scale: The Persistence, Effort, Resilience and Challenge-Seeking Task (PERC). Journal of Learning Analytics, v. 7, n. 1, p. 5–18, 29 Mar. 2020.