1. The F-4 and the F-14;Sponsler,1973
2. Droop nose;Goff;Flight International, Sutton, UK,,1971
3. https://en.wikipedia.org/wiki/Northern_gannet#/media/File:Gannet_(Morus_bassana),_Belmont_-_geo-graph.org.uk_-_529175.jpg, By Mike Pennington, CC BY-SA 2.0.
4. Barbarino S., Pecora R., Lecce L., Concilio A., Ameduri S., Calvi E. A. “A novel SMA-based concept for airfoil structural morphing,” J. Mater. Eng. Perform. Vol. 8, N.5, pp. 696–705, 2009.
5. Elastomer-based skin for seamless morphing of adaptive wings;Schorsch,2016