1. The first 1,000 commercial UAS exemptions;Kesselman,2014
2. Energy: production, conversion, storage, conservation, and coupling;Demirel,2012
3. Case studies of energy storage with fuel cells and batteries for stationary and mobile applications;Belmonte;Challenges,2017
4. Commercial drone shipments to surpass 2.6 million units annually by 2025;Tractica,2015
5. World civil unmanned aerial systems market profile & forecast;Finnegan,2016