1. Backs, R. W. & Ryan, A. M. (1992). Multimodal measures of mental workload during dual-task performance: Energetic demands of cognitive processes. Proceedin&ls o f the Human Factors Society 36thAnnual Meeting (pp. 1413-1417). Santa Monica, CA: Human Factors Society.
2. Psychophysiological Measures of Workload during Continuous Manual Performance
3. Metabolic and cardiorespiratory measures of mental effort: the effects of level of difficulty in a working memory task
4. Comens, P., Reed, D. & Mette, M. (1987). Physiologic responses of pilots flying high-performance aircraft. Aviation, Space, and Environmental Medicine, 58, 205-210.