1. SESAR J.U., "European ATM Master Plan: roadmap for the safe integration of drones into all classes of airspace," 2017. [Online]. Available: https://www.sesarju.eu/sites/default/files/documents/reports/European%20ATM%20Master%20Plan%20Drone%20roadmap.pdf.
2. McKinsey analysis; Teal Group, "World civil unmanned aerial systems market profile & forecast," 2017.
3. "Commission implementing regulation (EU)," [Online]. Available: https://eur-lex.europa.eu/eli/reg_impl/2019/947/oj. [Accessed 02 May 2020].
4. "Commission delegated regulation (EU)," [Online]. Available: https://eur-lex.europa.eu/eli/reg_del/2019/945/oj. [Accessed 02 May 2020].
5. "Special condition for VTOL," [Online]. Available: https://www.easa.europa.eu/document-library/product-certification-consultations/special-condition-vtol. [Accessed 02 May 2020].