@article{https://resolver.caltech.edu/CaltechAUTHORS:20170123-081714017, title = "Swarm-Keeping Strategies for Spacecraft Under J\_2 and Atmospheric Drag Perturbations", journal = "Journal of Guidance, Control, and Dynamics", year = "2012", url = "https://resolver.caltech.edu/CaltechAUTHORS:20170123-081714017", id = "record", issn = "0731-5090", doi = "10.2514/1.55705", volume = "35" }