See, e.g., Marlow Anderson, Victor J. Katz, Robin J. Wilson, Sherlock Holmes in Babylon and Other Tales of Mathematical History, Mathematical Association of America, 2004, p. 114.
doi.org
Malet, Antoni (1993). „James Gregorie on tangents and the "Taylor" rule for series expansions”. Archive for History of Exact Sciences. Springer-Verlag. doi:10.1007/BF00375656. „Gregorie's thought, on the other hand, belongs to a conceptual framework strongly geometrical in character. (page 137)”