1. Directive 2014/24/EU of the European Parliament and of the Council of 26 February 2014 on public procurement and repealing Directive 2004/18/EC Text with EEA relevance (2014)
2. Directive 2014/25/EU of the European Parliament and of the Council of 26 February 2014 on procurement by entities operating in the water, energy, transport and postal services sectors and repealing Directive 2004/17/EC Text with EEA relevance (2014)
3. Digital procurement. https://single-market-economy.ec.europa.eu/single-market/public-procurement/digital-procurement_en
4. Kierkegaard, S.: Going, going, gone! e-procurement in the EU (2008)
5. European Commission: New European interoperability framework: promoting seamless services and data flows for European public administrations. DG Informatics, LU (2017)