1. Kepler J., Mysterium cosmographicum (Tübingen, 1596), 7: “Inter Iouem & Martem interposui nouum Planetam ….”.
2. Hegel G. W. F., Dissertatio philosophica de orbitis planetarum (Jena, 1801), reprinted in Georg Wilhelm Friedrich Hegel Sämtliche Werke, ed. by Lasson G., i (Leipzig, 1941), 347–401 (with German translation).
3. Grosser Morton, The discovery of Neptune (Cambridge, Mass., 1962), 32.