1. Eurostat database [Online]. Available: http://ec.europa.eu/eurostat.
2. Thermal insulation alternatives of historic brick buildings in Baltic Sea Region;Zagorskas;Energy and Buildings,2014
3. Central Statistical Bureau of Latvia, database [Online]. Available: http://www.csb.gov.lv.
4. Ēku renovācijas ilgtermiņa stratēģija 2014.–2020.gadam [Long term renovation strategy of buildings 2014-2020]. Ministry of Economy of Latvia, 2014.