WASET
    Yanan Yang and  Zhigang Wang and  Xiang Chen,  An Optimization of Orbital Transfer for Spacecrafts with Finite-thrust Based on Legendre Pseudospectral Method.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    August 2012, vol. 68(8). 1041 - 1045
    [viewed 04 May 2024]. Available from: https://publications.waset.org/pdf/6319.