1. Commission Implementing Regulation (EU) 2019/947 of 24 May 2019 on the rules and procedures for the operation of unmanned aircraft. [online]. 2019. Available from: https://eur-lex.europa.eu/eli/reg_impl/2019/947/oj
2. Commission Delegated Regulation (EU) 2019/945 of 12 March 2019 on unmanned aircraft systems and on third-country operators of unmanned aircraft systems. [online]. 2019. Available from: https://eur-lex.europa.eu/eli/reg_del/2019/945/oj
3. European Commission Decision C (2020)1862 of 25 March 2020: Horizon 2020 Work Programme 2018-2020, 11. Smart, green and integrated transport. PDF. [online]. Available from: https://ec.europa.eu/research/participants/data/ref/h2020/wp/2018-2020/main/h2020-wp1820-transport_en.pdf
4. European Union Aviation Safety Agency (EASA), 2020. Opinion No 01/2020, High-level regulatory framework for the U-space [online]. Available from: https://www.easa.europa.eu/sites/default/files/dfu/Opinion%20No%2001-2020.pdf
5. An Introduction to Discourse Analysis: Theory and Method;Gee,2014