1. Council Directive 89/106/EEC of 21 December 1988 on the approximation of laws, regulations and administrative provisions of the Member States relating to construction products, Official Journal L 040 (11 February 1989) 0012–0026.
2. Lithuanian energy efficiency project, Eduardas Kazakevicius, Aloyzas Vitkauskas, Svend Erik Mikkelsen, Energy Policy, vol. 30, issue 7, Elsevier, Amsterdam, 2002, pp. 621–627.
3. W.P. Vijfwinkel, V. Martinaitis, Efficiency of building renovation, results of monitoring, energy for buildings, in: Proceedings of the fourth International Conference, Vilnius, Lithuania, ISBN 9955-401-54-0, Litimo, Vilnius, 21–22 September 2000, pp. 199–206.
4. Short-term consultancy for review and analysis of experiences from recently renovated schools in Lithuania: Report, Client: Ministry of Education and Science of Republic of Lithuania, Executor: JSC Eksergija, 2001, 230 pp.
5. A. Meier, The cost of conserved energy as an investment statistic, Heating, Piping, Air Conditioning, 55 (September) (1983) 73–77.