Title: Sphaera mundi
Subjects: Astronomy, Cosmography, Early works to 1800, Planetary theory, Spherical astronomy, Navigation, Measurement, Roland (Legendary character), History and criticism, Civilization, Medieval, in literature, Romances, Planets, Church calendar, Church history, Chronology
People: Gerardus Cremonensis, of Sabbioneta (13th cent), Gherardo da Sabbioneta (13th cent)