D. Kacandolli - Gjonbala, J. Shiroka - Pula, A. Berisha - Shaqiri, and M. Osmani, “The Efficiency of Public Procurement in the Republic of Kosovo: an Econometric Approach”, ECO, vol. 97, no. 2, pp. 70–90, Oct. 2018, doi: 10.15388/Ekon.2018.1.11787.