Negri, Rodolfo B.; Prado, Antonio F. B. A. (2020). "Generalizing the Bicircular Restricted Four-Body Problem". Journal of Guidance, Control, and Dynamics. 43 (6): 1173–1179. Bibcode:2020JGCD...43.1173N. doi:10.2514/1.G004848. S2CID213600592.
Xia, Zhihong (May 1992). "The Existence of Noncollision Singularities in Newtonian Systems". Ann. Math. Second Series. 135 (3): 411–468. doi:10.2307/2946572. JSTOR2946572.
Negri, Rodolfo B.; Prado, Antonio F. B. A. (2020). "Generalizing the Bicircular Restricted Four-Body Problem". Journal of Guidance, Control, and Dynamics. 43 (6): 1173–1179. Bibcode:2020JGCD...43.1173N. doi:10.2514/1.G004848. S2CID213600592.
Xia, Zhihong (May 1992). "The Existence of Noncollision Singularities in Newtonian Systems". Ann. Math. Second Series. 135 (3): 411–468. doi:10.2307/2946572. JSTOR2946572.
Negri, Rodolfo B.; Prado, Antonio F. B. A. (2020). "Generalizing the Bicircular Restricted Four-Body Problem". Journal of Guidance, Control, and Dynamics. 43 (6): 1173–1179. Bibcode:2020JGCD...43.1173N. doi:10.2514/1.G004848. S2CID213600592.