Renzulli, J. S., Del Siegle, E., Reis, S. M., Gavin, K. M. & Systma Reed, R. E. (2009). An investigation of the reliability and factor structure of four news Scales for Rating the Behavioral Characteristics of Superior Studentes. Journal of Advanced Academics, 21, (1), 84-108. https://files.eric.ed.gov/fulltext/EJ880576.pdf