Article Heis, Jeremy (2010)
“Critical Philosophy Begins at the Very Point Where Logistic Leaves Off”: Cassirer's Response to Frege and Russell. Perspectives on Science (p. 383). (/isis/citation/CBB001034595/) unapi

Article Edgar, Scott (2008)
Paul Natorp and the Emergence of Anti-Psychologism in the Nineteenth Century. Studies in History and Philosophy of Science (p. 54). (/isis/citation/CBB000930747/) unapi

Article Pulkkinen, Jarmo (2001)
Russell and the neo-Kantians. Studies in History and Philosophy of Science (p. 99). (/isis/citation/CBB000100800/) unapi

Chapter Peiffer-Reuter, Renée (1989)
L'infini relatif chez Veronese et Natorp: Un chapitre de la préhistoire d l'analyse non-standard. In: La mathématique non standard: Histoire, philosophie, dossier scientifique. Avec une préface de Georges Reeb (p. 117). (/isis/citation/CBB000065100/) unapi

Book Arlt, Gerhard (1985)
Subjektivität und Wissenschaft: Zur Psychologie des Subjekts bei Natorp und Husserl. (/isis/citation/CBB000060326/) unapi