Neagu, M. I., and M. C. Teodoru. “Testing the Engel’s Law in the Consumption Pattern of Romanian Population”. Studia Universitatis Vasile Goldiș Arad, Seria Științe Economice, Vol. 27, no. 3, Sept. 2017, pp. 33-53, https://publicatii.uvvg.ro/index.php/studiaeconomia/article/view/188.