APOSTOL, T. M. Y MAMIKON, A. M. (2002): Subtangents. An aid to visual calculus. The American Math. Monthly, vol. 109, no 6, 525-533. APOSTOL, T. M. Y MAMIKON, A. M. (2002): Tangents and sub- tangents used to calculate areas. The American Math. Monthly, vol. 109, no 10, 900-907. ARAO, J. (2000): Tangents without calculus. The College Math. Journal, vol. 31, no 5, 406-407. BARNIER, W. (2007): Descartes tangent lines. The College Math. Journal, vol. 38, no 1, 47-49. BIVENS I. C. (1986): What a tangent line is when it isn ́t a limit. The College Math. Journal, vol. 17, no 2, 133-143. COOLIGE, J. L. (1951): The story of tangents. The American Math. Monthly, vol. 58, no 7, 449-462. EDDY R. H. Y FRITSCH, R. (1994): An optimization oddity. The College Math. Journal, vol. 25, no 3, 227-229. GRABINER, J. V. (1983): The changing concept of change: the deriv- ative from Fermat to Weiertrass. Mathematics Magazine, vol. 56, no 4, 195-206. MARTINEZ DE LA ROSA, F. (2004): Aportaciones a la matemática visual. Epsilon, vol. 20, no 60, 449-459. PARÉ, R. (1995): A visual proof of Eddy and Fritsch’s minimal area property. The College Math. Journal, vol. 26, no 1, 43-44. SKALA, H. (1997): A discover-e. The College Math. Journal, vol. 28, no 2, 128-129. SUZUKI, J. (2005): The lost Calculus (1637-1670): Tangency and optimization without limits. Mathematics Magazine, vol.78, no 5, 339-353. THURSTON H. (1969): Tangents: an elementary surveys. Mathematics Magazine, vol. 41, no 1, 1-11. WOLFSON P. R. (2001): The crooked made straight: Roberval and Newton on tangents. The American Math. Monthly, vol. 108, no 3, 206-216.
