1. The effect of aerofoil characteristics on windmill performance;Griffiths,1977
2. On the vortex theory of airscrews;Goldstein,1929
3. Appendix to ‘Schraubenpropeller mit geringstem Energieverlust’ by Betz, A.;Prandtl,1919
4. Performance-optimised horizontal-axis wind turbines;Wilson,1976