Brieskorn, Egbert; Knörrer, Horst (1986). Plane algebraic curves. Modern Birkhäuser Classics. Translated by Stillwell, John. Birkhäuser/Springer Basel AG. p. 16. doi:10.1007/978-3-0348-5097-1. ISBN978-3-0348-0492-9. MR2975988. The word σπειρα originally meant a coil of rope, and came to refer to the base of a column, which for certain orders of column was shaped as a torus: see Yates, James (1875). "Spira". In Smith, William (ed.). A Dictionary of Greek and Roman Antiquities. London: John Murray.
books.google.com
Brieskorn, Egbert; Knörrer, Horst (1986). Plane algebraic curves. Modern Birkhäuser Classics. Translated by Stillwell, John. Birkhäuser/Springer Basel AG. p. 16. doi:10.1007/978-3-0348-5097-1. ISBN978-3-0348-0492-9. MR2975988. The word σπειρα originally meant a coil of rope, and came to refer to the base of a column, which for certain orders of column was shaped as a torus: see Yates, James (1875). "Spira". In Smith, William (ed.). A Dictionary of Greek and Roman Antiquities. London: John Murray.
doi.org
Brieskorn, Egbert; Knörrer, Horst (1986). Plane algebraic curves. Modern Birkhäuser Classics. Translated by Stillwell, John. Birkhäuser/Springer Basel AG. p. 16. doi:10.1007/978-3-0348-5097-1. ISBN978-3-0348-0492-9. MR2975988. The word σπειρα originally meant a coil of rope, and came to refer to the base of a column, which for certain orders of column was shaped as a torus: see Yates, James (1875). "Spira". In Smith, William (ed.). A Dictionary of Greek and Roman Antiquities. London: John Murray.
uchicago.edu
penelope.uchicago.edu
Brieskorn, Egbert; Knörrer, Horst (1986). Plane algebraic curves. Modern Birkhäuser Classics. Translated by Stillwell, John. Birkhäuser/Springer Basel AG. p. 16. doi:10.1007/978-3-0348-5097-1. ISBN978-3-0348-0492-9. MR2975988. The word σπειρα originally meant a coil of rope, and came to refer to the base of a column, which for certain orders of column was shaped as a torus: see Yates, James (1875). "Spira". In Smith, William (ed.). A Dictionary of Greek and Roman Antiquities. London: John Murray.