The inverse N -body problem. A geometrical approach R. Weder (1994/1995) Séminaire Équations aux dérivées partielles (Polytechnique)
The measurable distinction between the spin and orbital angular momenta of electromagnetic radiation. Crichton, James H., Marston, Philip L. (2000) Electronic Journal of Differential Equations (EJDE) [electronic only]
The Role of Green’s Functions in Inverse Scattering at Fixed Energy James Ralston (1996/1997) Séminaire Équations aux dérivées partielles