On those Principles of Mechanics which depend upon Processes of Variation Philip E.B. Jourdain — 1908 Mathematische Annalen
The derivation of Equations in Generalised Coordinates from the Principle of Least Action and allied Principles Philip E.B. Jourdain — 1906 Mathematische Annalen
On the general theory of functions. Philip E.B. Jourdain — 1905 Journal für die reine und angewandte Mathematik