1. Drone noise levels,2020
2. Introduction of a regulatory framework for the operation of unmanned aircraft systems in the ‘open’ and ‘specific’ categories,2018
3. FAA Aerospace Forecast, Fiscal Years 2019-2039,2022
4. Drone technology uses and applications for commercial, industrial and military drones in 2021 and the future,2021
5. ISO 9613-2:1996 Acoustics – Attenuation of sound during propagation outdoors: Part 2: General method of calculation,1996