Tài liệu tham khảo WikiPedia: 473_Nolli http://cfa-www.harvard.edu/iauc/04200/04292.html#I... http://www.psi.edu/pds/resource/family.html http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&b... http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=473;orb=1