Rohil, V., Vijayan, V.K., Kumar, R., Joshi, R., Pavani, P., Paul, S., Sharma, A. and Rahman, M. ur 2017. A study on the correlation of matrix metalloproteinase MMP1 in COPD and smoking in the North Indian population. Asian Journal of Medical Sciences. 8, 1 (Jan. 2017), 5–14. DOI:https://doi.org/10.3126/ajms.v8i1.16020.