Detlef Laugwitz

Detlef Laugwitz (1932-2000) was a mathematician and historian of mathematics. He published the standard biography of Bernhard Riemann in 1996. He authored a series of publications in professional history of mathematics journals on both Euler and Cauchy. See

Laugwitz, D. (1987). Infinitely small quantities in Cauchy's textbooks. Historia Mathematica 14, 258-274.

Laugwitz, D. (1989). Definite values of infinite sums: aspects of the foundations of infinitesimal analysis around 1820. Archive for History of Exact Sciences 39 (3): 195-245. https://link.springer.com/article/10.1007/BF00329867