LATTANZI, Mario G.; MASSONE, Giuseppe; MUNARI, Ulisse. Memberships and CM diagrams of young open clusters. I - NGC 225. S. 177–199. Astronomical Journal [online]. Červenec 1991 [cit. 2019-10-22]. Roč. 102, s. 177–199. Dostupné online. DOI10.1086/115865. Bibcode1991AJ....102..177L. (anglicky)
COLLINDER, Per. On Structural Properties of Open Galactic Clusters and their Spatial Distribution. Catalog of Open Galactic Clusters. S. B1-B46. Annals of the Observatory of Lund [online]. 1931 [cit. 2019-10-22]. Čís. 2, s. B1-B46. Dostupné online. Bibcode1931AnLun...2....1C. (anglicky)
LATTANZI, Mario G.; MASSONE, Giuseppe; MUNARI, Ulisse. Memberships and CM diagrams of young open clusters. I - NGC 225. S. 177–199. Astronomical Journal [online]. Červenec 1991 [cit. 2019-10-22]. Roč. 102, s. 177–199. Dostupné online. DOI10.1086/115865. Bibcode1991AJ....102..177L. (anglicky)
COLLINDER, Per. On Structural Properties of Open Galactic Clusters and their Spatial Distribution. Catalog of Open Galactic Clusters. S. B1-B46. Annals of the Observatory of Lund [online]. 1931 [cit. 2019-10-22]. Čís. 2, s. B1-B46. Dostupné online. Bibcode1931AnLun...2....1C. (anglicky)
LATTANZI, Mario G.; MASSONE, Giuseppe; MUNARI, Ulisse. Memberships and CM diagrams of young open clusters. I - NGC 225. S. 177–199. Astronomical Journal [online]. Červenec 1991 [cit. 2019-10-22]. Roč. 102, s. 177–199. Dostupné online. DOI10.1086/115865. Bibcode1991AJ....102..177L. (anglicky)