Bhattacharya, R.; Chowdhury, S.; Nandi, A.; Mukherjee, R.; Kulshrestha, M.; Ghosh, R.; Saha, S. Pre-Exposure Hydroxychloroquine Prophylaxis for COVID-19 in Healthcare Workers: A Retrospective Cohort. Int J Res Med Sci 2020, 9, 89-96.