“On a Flawed, 16th-Century Derivation of Brahmagupta’s Formula for the Area of a Cyclic Quadrilateral,” Forum Geometricorum 15 (2015), pp.165-172.
“From Brahmagupta to Euler: On the Formula for the Area of a Cyclic Quadrilateral,” BSHM Bulletin. Journal of the British Society for History of Mathematics 30(2015), pp. 20-34.
(with Gerard Buskes) “Engel’s Ingenious Models: On the Models of the Fresnel Wave Surface at the University of Mississippi,” Rittenhouse – Journal of the American Scientific Instrument Enterprise 22:1 (2009) (special issue), pp. 90-112.
“On n-Sections and Reciprocal Quadrilaterals,” Forum Geometricorum 9 (2009), pp. 1-17.
“An Elementary Proof of a Theorem by Emelyanov,” Forum Geometricorum 8 (2008), pp. 201-204.
“Butterflies in Quadrilaterals: A Comment on a Note by Sidney Kung,” Mathematics Magazine 80:1 (Febr. 2007), pp. 70-72.
“A Theorem by Giusto Bellavitis on a Class of Quadrilaterals,” Forum Geometricorum 6 (2006), pp. 181-185.
“Into the Woods: Wiener in Maine,” The Mathematical Intelligencer 25:2 (Spring 2003), pp. 7-17.
“Beyond Monge’s Theorem: A Generalization of the Pythagorean Theorem,” Mathematics Magazine 73:4 (Oct. 2000), pp. 293-296.
(with R. H. Vermij) “Specilla Circularia: an Unknown Work by Johannes Hudde,” Studia Leibnitiana XXVII/1 (1995), pp.104-121
“Letters from Luigi Cremona to Julius Plücker (1867-1868), ” (in Italian) La Corrispondenza di Luigi Cremona (1830-1903), vol. II (= Serie di Quaderni della Rivista di Storia della Scienza, n.3 (1994)), pp. 73-77.
“All Phenomena of Optics that depend on Mathematics – A Sketch of the Development of 19th Century Geometrical Optics,” Tractrix. Yearbook for the Dutch Society for the History of Science, vol.5 (1993), pp. 45-80.
Book Chapters (Refereed)
“Charles-François Sturm’s Writings on Optics.” In: J.-C. Pont (e.a.) (Eds) Collected Works of Charles-François Sturm (Basel: Birkhäuser, 2009), pp.49-68.
(with H. White) “Euler on Cevians.” In: A. Shell-Gellasch & R. Jardine (Eds) From Calculus to Computers. Using the Last 200 Years of Mathematics History in the Classroom (= MAA Notes #68) (Washington: MAA, 2005), pp. 75-91.
(with G. Alberts & J.A. van Maanen) “Mathematics in the Netherlands: A Brief Survey, with an Emphasis on the Relation to Physics, 1560-1960.” In: K. van Berkel (e.a.) (Eds) A History of Science in the Netherlands. Survey, Themes and Reference (Leiden: Brill, 1999), pp. 367-399.
“A Theory of Caustics – The Contribution of Dupin, Quetelet, and Gergonne to Geometrical Optics.” In: A. von Gotstedter (Ed.), Ad Radices. IGN Jubiläumsband (Steiner Verlag Stuttgart, 1995), pp. 331-354.
Conference Papers (Refereed)
“A Most Elegant Property: On the Early History of Lexell’s Theorem” In: Dirk Schlimm and Maria Zack (eds), Research in History and Philosophy of Mathematics. The CSHPM 2016 Annual Meeting in Calgary, Alberta (Birkhauser, 2017), pp. 117-132.
“Mathematics Textbook Reform in the Progressive Era: The Case of David Eugene Smith.” In: Monique Lebrun e.a. (eds), Le manuel scolaire, d’ici et d’ailleurs, d’hier à demain (Montréal: PUQ, 2007) (file 10-04.pdf on accompanying CD-ROM; 15 pp.).
Reference Works Entries
“Richard van Rees (1797-1875).” (in Dutch) In: Biographisch Woordenboek van Nederlandse Wiskundigen (BWNW) (an on-line dictionary of Dutch mathematicians).
“Johan Frederik Hennert (1733-1813).” (in Dutch) In: Biographisch Woordenboek van Nederlandse Wiskundigen (BWNW) (an on-line dictionary of Dutch mathematicians).
“Table 1: Geometrical Optics in the 19th Century.” (in Italian) In: Sandro Petruccioli e.a. (eds.) Storia della Scienza (Rome: Istituto della Enciclopedia Italiana, 2001-2004). Vol. 7 (2002), p.345
Outreach
“When More is Not Always Better: On How Not to Approach an Elementary Construction Problem,” GeT: The News Volume 1, Issue 3 (Spring, 2020), pp.1, 4-5 (= Newsletter for the GRIP Group, School of Education, University of Michigan).
(with Geoff Lambert) “An Italian Lesson in Timetable Reading,” The Times. Journal of the Australian Association of Timetable Collectors 19:8 (August 2002), pp. 11-15.
“Sonia Kovalevskaia,” (in Dutch) Pythagoras, 3 (1997/8), p.4.
“Christiaan Huygens and the 19th Century: the Road to the Oeuvres Complètes,” (in Dutch) De Prate-banck. Informatiebulletin van Vereniging Hofwijck afl. 2.4 (1995), pp. 3-7.
“Dirk Struik – Centenarian!!,” (in Dutch) Nieuwe Wiskrant. Tijdschrift voor Nederlands Wiskundeonderwijs vol. 14.2 (1995), pp. 27-31.
“On Caustic Curves and their Determination,” (in Dutch) Vakantiecursus 1994 Computer Algebra (= CWI Syllabus 36), pp.26-41.