Jabarkan Bacaan lebih lanjut dari Moritz Schlick

Holt, Jim, "Positive Thinking" (ulasan Karl Sigmund, Exact Thinking in Demented Times:  The Vienna Circle and the Epic Quest for the Foundations of Science, Buku Dasar, hlm. 449), The New York Review of Books, vol. LXIV, no. 20 (21 Desember 2017), pp. 74–76.