Fiok, K., Karwowski, W., Gutierrez, E., Saeidi, M., Aljuaid, A. M., Davahli, M. R., … & Sawyer, B. D. (2021). A Study of the Effects of the COVID-19 Pandemic on the Experience of Back Pain Reported on Twitter® in the United States: A Natural Language Processing Approach. International Journal of Environmental Research and Public Health, 18(9), 4543. PDF