K. D. Ro and  J. T. Park and  J. H. Kim,  Hydrodynamic Characteristics of Weis–Fogh Type Ship-s Propulsion Mechanism Having Elastic Wing.   journal   = {International Journal of Aerospace and Mechanical Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2009, vol. 30(6). 684 - 689
    [viewed 19 April 2024]. Available from: https://publications.waset.org/pdf/3161.