Lloréns-Bonilla, Aidaliz, et al. “Severe Intractable Headache As a Presentation of COVID-19 in a 23-Year-Old”. Puerto Rico Health Sciences Journal, vol. 41, no. 2, May 2022, pp. 100-3, https://prhsj.rcm.upr.edu/index.php/prhsj/article/view/2565.