1. Natural frequencies in bending of twisted rotating and non-rotating beams;Isakson;NASA TN D-371,1960
2. Load prediction methods for hingeless rotor helicopters;Reichert;Specialists Mtng. on Helicopter Rotor Loads Prediction Methods, AGARD-CP-122,1973
3. The vibration of blades in axial turbomachinery;Research;Report No. 1088, AD 645156,1965
4. Dynamical analysis of the shaft-fixed helicopter blade;Sobey;RAE TR 73175,1974