The letter of Petrus Peregrinus on the magnet, A.D. 1269 Translated by Brother Arnold (New York, McGraw Publishing, 1904) (online)
J. Taisnier, Opusculum perpetua memoria dignissimum, de natura magnetis et ejus effectibus, Item de motu continuo (Apud Joannem Birckmannum, Cologne 1562). Pageviews at Google.
