Chapter Ullrich, Peter (2005)
Herkunft, Schul- und Studienzeit von Carl Friedrich Gauß. In: “Wie der Blitz einschlägt, hat sich das Räthsel gelöst”: Carl Friedrich Gauß in Göttingen (p. 17). (/isis/citation/CBB001232256/) unapi

Book Biegel, Gerd; Oestmann, Günther; Reich, Karin (2001)
Neue Welten: Wilhelm Olbers und die Naturwissenschaften um 1800. (/isis/citation/CBB000102408/) unapi

Article Ullrich, Peter (2000)
The Poincaré-Volterra Theorem: From Hyperelliptic Integrals to Manifolds with Countable Topology. Archive for History of Exact Sciences (p. 375). (/isis/citation/CBB000740287/) unapi

Chapter Ullrich, Peter (1998)
The genesis of Hensel's p-adic numbers. In: Charlemagne and his heritage: 1200 years of civilization and science in Europe. Volume 2: Mathematical arts (p. 163). (/isis/citation/CBB000082291/) unapi

Article Ullrich, Peter (1996)
The Riemann mapping problem. Studies in the History of Modern Mathematics: Supplemento di Rendiconti del Circolo Matematico di Palermo (pp. 9-42). (/isis/citation/CBB000076492/) unapi

Chapter Ullrich, Peter (1994)
The proof of the Laurent expansion of Weierstrass. In: The history of modern mathematics (p. 139). (/isis/citation/CBB000042332/) unapi

Chapter Ullrich, Peter (1994)
The Riemann removable singularity theorem from 1841 onwards. In: The history of modern mathematics (p. 155). (/isis/citation/CBB000042433/) unapi

Article Ullrich, Peter (1989)
Weierstrass' Vorlesung zur “Einleitung in die Theorie der analytischen Funktionen”. Archive for History of Exact Sciences (pp. 143-172). (/isis/citation/CBB000035399/) unapi