Christian F. Clarenbach (2016) “Periostin Levels do not Distinguish Chronic Obstructive Pulmonary Disease Patients With Frequent and Infrequent Exacerbations”, Pulmonary Research and Respiratory Medicine, 3(2), pp. 33–36. Available at: https://openventio.us/index.php/PRRM/article/view/2152 (Accessed: 7 September 2026).