Absolut brightness of comet Ikya-Seki 1965 f and of other comets of Kreutz's group Jiří Bouška (1966) Acta Universitatis Carolinae. Mathematica et Physica Similarity:
Supplementary catalogue I of original and future comet orbits Zdeněk Sekanina (1968) Acta Universitatis Carolinae. Mathematica et Physica Similarity: