@masterthesis{3361960,
    title = "Exploring Obata's theorem: Insights and Applications in Differential Geometry",
    authorField = "Καλογερής, Ιωάννης",
    year = "2023",
    school = "ΠΜΣ Μαθηματικά, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών"
}