Mioc, Vasile, and Eugenia Radu. “A Complete First Order Approximation for the Motion in a Noncentral Attraction Field”. Rev. Anal. Numér. Théor. Approx. 22, no. 1 (February 1, 1993): 67–71. Accessed May 14, 2024. https://ictp.acad.ro/jnaat/journal/article/view/1993-vol22-no1-art6.