Lubin, Dan; et al. (March 2012), "Frequency of Maunder Minimum Events in Solar-type Stars Inferred from Activity and Metallicity Observations", The Astrophysical Journal Letters, 747 (2): 6, Bibcode:2012ApJ...747L..32L, doi:10.1088/2041-8205/747/2/L32, L32.
Takeda, Yoichi; et al. (February 2005), "High-Dispersion Spectra Collection of Nearby F--K Stars at Okayama Astrophysical Observatory: A Basis for Spectroscopic Abundance Standards", Publications of the Astronomical Society of Japan, 57 (1): 13–25, Bibcode:2005PASJ...57...13T, doi:10.1093/pasj/57.1.13.
Hempelmann, A.; et al. (February 2016), "Measuring rotation periods of solar-like stars using TIGRE. A study of periodic CaII H+K S-index variability", Astronomy & Astrophysics, 586: 19, Bibcode:2016A&A...586A..14H, doi:10.1051/0004-6361/201526972, A14.
Lubin, Dan; et al. (March 2012), "Frequency of Maunder Minimum Events in Solar-type Stars Inferred from Activity and Metallicity Observations", The Astrophysical Journal Letters, 747 (2): 6, Bibcode:2012ApJ...747L..32L, doi:10.1088/2041-8205/747/2/L32, L32.
Takeda, Yoichi; et al. (February 2005), "High-Dispersion Spectra Collection of Nearby F--K Stars at Okayama Astrophysical Observatory: A Basis for Spectroscopic Abundance Standards", Publications of the Astronomical Society of Japan, 57 (1): 13–25, Bibcode:2005PASJ...57...13T, doi:10.1093/pasj/57.1.13.
Hempelmann, A.; et al. (February 2016), "Measuring rotation periods of solar-like stars using TIGRE. A study of periodic CaII H+K S-index variability", Astronomy & Astrophysics, 586: 19, Bibcode:2016A&A...586A..14H, doi:10.1051/0004-6361/201526972, A14.