Washington Irving (2015). “The Complete Works of Washington Irving: Short Stories, Plays, Historical Works, Poetry and Autobiographical Writings (Illustrated): The Entire Opus of the Prolific American Writer, Biographer and Historian, Including The Legend of Sleepy Hollow, Rip Van Winkle, The Sketch Book of Geoffrey Crayon, Bracebridge Hall and many more”, p.1619, e-artnow
Colin MacLaurin (1756). “A Treatise of Algebra, in Three Parts: Containing I. The Fundamental Rules and Operations; II. The Composition and Resolution of Equations of All Degrees, and the Different Affections of Their Roots; III. The Application of Algebra and Geometry to Each Other. To which is Added an Appendix Concerning the General Properties of Geometrical Lines”, p.1