1594. Nashe, Christ’s T. (ed. 2), To Rdr. Henceforth … for an vnrefutable principle I will hold it.
1629. Massinger, Picture, IV. ii. As I must grant, It being vnrefutable in reason.
1859. Herschel, Pop. Lect. Sci., iii. § 54 (1866), 140. That positive and unrefutable demonstration.
