1. Acosta, T. (2023). In this sliver of Arizona, letters arrive by mule. After 100 years, it’s still the only way. AZ Central. https://www.azcentral.com/story/travel/arizona/grand-canyon/2023/09/15/grand-canyon-mule-mail-delivery/70702717007/
2. Air Force. (2023). MQ-9 Reaper. United States Air Force. https://www.af.mil/About-Us/Fact-Sheets/Display/Article/104470/mq-9-reaper/
3. Almeida, D. R. A., Broadbent, E. N., Zambrano, A. M. A., Wilkinson, B. E., Ferreira, M. E., Chazdon, R., Meli, P., Gorgens, E. B., Silva, C. A., Stark, S. C., Valbuena, R., Papa, D. A., & Brancalion, P. H. S. (2019). Monitoring the structure of forest restoration plantations with a drone-lidar system. International Journal of Applied Earth Observation and Geoinformation, 79, 192–198. https://doi.org/10.1016/j.jag.2019.03.014
4. Amazon. (2023). Amazon sidewalk. Amazon. https://www.amazon.com/Amazon-Sidewalk/b?ie=UTF8&node=21328123011
5. Amponis, G., Lagkas, T., Zevgara, M., Katsikas, G., Xirofotos, T., Moscholios, I., & Sarigiannidis, P. (2022). Drones in B5G/6G networks as flying base stations. Drones, 6(2), 39. https://doi.org/10.3390/drones6020039