- The Theory Of Permutable Functions (1915)
- Drei Vorlesungen Uber Neuere Fortschritte Der Mathematischen Physik: Gehalten Im September 1909 an Der Clark-University
- The theory of permutable functions. Lectures delivered at Princeton University October, 1912
- Theory of Functionals and of Integral and Integro-Differential Equations (Dover Phoenix Editions)
- Saggi scientifici (Italian Edition)