Paas, Fred G. W. C.; Van Merriënboer, Jeroen J. G. (23 November 2016). "The Efficiency of Instructional Conditions: An Approach to Combine Mental Effort and Performance Measures". Human Factors: The Journal of the Human Factors and Ergonomics Society. 35 (4): 737–743. doi:10.1177/001872089303500412. S2CID67201799.
Paas, Fred G. W. C.; Van Merriënboer, Jeroen J. G. (23 November 2016). "The Efficiency of Instructional Conditions: An Approach to Combine Mental Effort and Performance Measures". Human Factors: The Journal of the Human Factors and Ergonomics Society. 35 (4): 737–743. doi:10.1177/001872089303500412. S2CID67201799.