Aji, G., Manuaba, I. A. R. W., Ongkowijaya, J. A., Setiyohadi, B. and Sumariyono, S. (2018) “Correlation of matrix metalloproteinase-9 level, erythrocyte sedimentation rate, rheumatoid factor, and the duration of illness with radiological findings in rheumatoid arthritis patients”, Indonesian Journal of Rheumatology, 2(1). doi: 10.37275/ijr.v2i2.32.