The volume 4 of the scientific works of Charles de La Vallée Poussin is now available and includes de La Vallée Poussin's contributions to Potential Theory, Conformal Representation and Complex Variables.
This achieves the impressive effort undertaken by Profs. Paul Butzer (Aachen), Jean Mawhin (UCL) and Pasquale Vetro (Palermo) to gather and publish the entire mathematical contribution of de La Vallée Poussin, which spans over more than 100 papers in various research topics.
The previous volumes are
Vol. 1 - Biography and Number Theory
Vol. 2 - Measure and Integration, Probability, ODE, Mechanics, Geometry
Vol. 3 - Approximation Theory, Fourier Analysis and Quasi-Analytic Functions
All volumes are jointly published by the Académie royale de Belgique and the Circolo Matematico di Palermo.
They can be ordered directly from the Académie royale de Belgique