Narita, Norio; et al. XO-2b: a Prograde Planet with a Negligible Eccentricity and an Additional Radial Velocity Variation. Publications of the Astronomical Society of Japan. 2011, 63 (6): L67–L71. Bibcode:2011PASJ...63L..67N. arXiv:1110.6136. doi:10.1093/pasj/63.6.l67.
Sing, D. K.; et al. Gran Telescopio Canarias OSIRIS transiting exoplanet atmospheric survey: detection of potassium in XO-2b from narrowband spectrophotometry. Astronomy and Astrophysics. 2011, 527. article number A73. Bibcode:2011A&A...527A..73S. arXiv:1008.4795. doi:10.1051/0004-6361/201015579.
Narita, Norio; et al. XO-2b: a Prograde Planet with a Negligible Eccentricity and an Additional Radial Velocity Variation. Publications of the Astronomical Society of Japan. 2011, 63 (6): L67–L71. Bibcode:2011PASJ...63L..67N. arXiv:1110.6136. doi:10.1093/pasj/63.6.l67.
Sing, D. K.; et al. Gran Telescopio Canarias OSIRIS transiting exoplanet atmospheric survey: detection of potassium in XO-2b from narrowband spectrophotometry. Astronomy and Astrophysics. 2011, 527. article number A73. Bibcode:2011A&A...527A..73S. arXiv:1008.4795. doi:10.1051/0004-6361/201015579.
Narita, Norio; et al. XO-2b: a Prograde Planet with a Negligible Eccentricity and an Additional Radial Velocity Variation. Publications of the Astronomical Society of Japan. 2011, 63 (6): L67–L71. Bibcode:2011PASJ...63L..67N. arXiv:1110.6136. doi:10.1093/pasj/63.6.l67.
Sing, D. K.; et al. Gran Telescopio Canarias OSIRIS transiting exoplanet atmospheric survey: detection of potassium in XO-2b from narrowband spectrophotometry. Astronomy and Astrophysics. 2011, 527. article number A73. Bibcode:2011A&A...527A..73S. arXiv:1008.4795. doi:10.1051/0004-6361/201015579.