Karpowicz Andrzej, Tazhbenova G., Tulegenova Zh., и Orynbekova G. «STABILITY OF FISCAL REVENUES IN EU: WHAT TO TAX?». Scientific Journal of Pedagogy and Economics, вып. 1, февраль 2020 г., сс. 207-1, http://89.250.84.46/bulletin-science/article/view/743.