Pilcher, Frederick (abril de 2011), «Rotation Period Determinations for 25 Phocaea, 140 Siwa, 149 Medusa 186 Celuta, 475 Ocllo, 574 Reginhild, and 603 Timandra», Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers, 38 (2), p. 76-78, Bibcode:2011MPBu...38...76P.