The Comet of Bethlehem: An Early Thirteenth-Century Representation by Nicholas of Verdun

Olson R. J. M. , “Giotto's portrait of Halley's Comet”, Scientific American, ccxl (1979), 160–70; Olson R. J. M. , Fire and ice: A history of comets in art (Washington, 1985); Olson R. J. M. and Pasachoff J. M. , “New information on Comet P/Halley as depicted by Giotto de Bondone and other Western artists”, Astronomy and astrophysics, clxxxvii (1987), 1–11 (also reprinted in Exploration of Halley's Comet, ed. by Grewing M. Praderie F. and Reinhard R. (Berlin, 1988), 1–11); Yeomans D. K. , Comets: A chronological history of observation, science, myth, and folklore (New York, 1991).

Olson , “Giotto's portrait of Halley's Comet”, 162.

Ibid., 166.

Olson R. J. M. and Pasachoff J. M. , “Is Comet P/Halley of a.d. 684 recorded in the Nuremberg chronicle?”, Journal for the history of astronomy, xx (1989), 171–4.

See Olson , Fire and ice, 11.

Yeomans , Comets, 396.