Zephyr and the development of high-altitude military surveillance drones – Drone Wars UK

Sensor, Shooter, Jammer – The Future of Intelligence, Surveillance, and Reconnaissance in the Urban Battlespace

Aviation – The Future is Unmanned – Time to Get Going India – Air Power Asia

Britain to purchase high altitude surveillance aircraft

High altitude platform systems (HAPS): technology trends

UK military buys third £4m Zephyr drone for 'persistent surveillance' trials • The Register

China to fly solar drone to near space - Asia Times

Drones Reach Stratospheric Heights in Race to Fly Higher, Longer - WSJ

Britain's New Spy Planes Are Practically Spacecraft, by War Is Boring, War Is Boring

Stratospheric drones to provide 5G wireless communications, Global Internet, Border Security and Military Surveillance – International Defense Security & Technology

Zephyr and the development of high-altitude military surveillance

Sensor, Shooter, Jammer – The Future of Intelligence, Surveillance, and Reconnaissance in the Urban Battlespace

So close! Zephyr drone lands just hours before setting flight-duration record