{Reference Type}: Letter
{Title}: GOLD 2021 guidelines for COPD - what's new and why.
{Author}: Gupta N;Malhotra N;Ish P;
{Journal}: Adv Respir Med
{Volume}: 89
{Issue}: 3
{Year}: 2021
暂无{DOI}: 10.5603/ARM.a2021.0015
{Abstract}: