Holzreuter, R. Department Sun and Heliosphere, Max Planck Institute for Solar System Research, Max Planck Society;
Bianda, M., Ramelli, R., Stenflo, J. O., Anusha, L. S., Nagendra, K. N., Sampoorna, M., et al. (2011). Observations of the Solar Ca i 4227 Å Line. ASPC, 67-71.