1. Public Utilities Commission of Latvia. Ūdenssaimniecības pakalpojumu tarifu aprēķināšanas metodika (in Latvian).
http://likumi.lv/doc.php?id=209845
2. National Commission for Energy Control and Prices of Lithuania. Geriamojo vandens tiekimo ir nuoteku tvarkymo bei paviršiniu nuoteku tvarkymo paslaugu kainu nustatymo metodika (in Lithuanian).
https://www.e-tar.lt/portal/lt/legalAct/4c3e62a08a9311e4a98a9f2247652cf4
3. Ziemele, J., Vigants, G., Vitolins, V., et al.: District heating systems performance analyses; heat energy tariff. Environ. Clim. Technol. 13(1), 32–43 (2014). Scientific J. of RTU
4. Guerrini, A., Romano, G., Campadelli, B.: Factors affecting the performance of water utility companies. Int. J. Pub. Sect. Manage. 24, 543–566 (2011)
5. Regulatory Implications of District Heating.
https://www.yumpu.com/en/document/view/35150691/regulatory-implications-of-district-heating