“Supplementation of curcumin and piperine plus standard therapy to prevent exacerbations in patients with Chronic Obstructive Pulmonary Disease (CUPISCO TRIAL: CUrcumin and PIperine Supplementation for COpd). A study protocol”., PPCR, vol. 6, no. 4, Feb. 2021, doi: 10.21801/ppcrj.2020.64.4.