Development and validation of nomogram to predict severe illness requiring intensive care follow up in hospitalized COVID-19 cases - Rahmet Guner; Bircan Kayaaslan; Imran Hasanoglu; Adalet Aypak; Hurrem Bodur; Ihsan Ates; Esragul Akinci; Deniz Erdem; Fatma Eser; Seval Izdes; Ayse Kaya Kalem; Aliye Bastug; et al. (BMC Infectious Diseases, 2021)