1. Drag Prediction Workshop held in NASA, June 2005.
2. Design synthesis and optimization of joined-wing transports;Gallman,1990
3. Induced-drag minimization of nonplanar geometries based on the Euler equations;Hicken;AIAA J.,2010
4. Minimum induced drag of wings with winglets;Jones,1980
5. ‘Non-planar wings for the increased span efficiency’ by Kroo, Stanford University, USA.