D. D. C. de F. Mota, C. A. de M. Pimenta, and M. I. Fitch, “Fatigue Pictogram: an option for assessing fatigue severity and impact”, Rev. Esc. Enferm. USP, vol. 43, no. spe, pp. 1080–1087, Dec. 2009, doi: 10.1590/S0080-62342009000500012.