1. Foundations of Antenna Radiation Theory
2. On the singularity expansion method for the solution of electromagnetic interaction problems;Baum C.E.;AFWL, Interaction Notes,1971
3. On the eigenmode expansion method for electromagnetic scattering and antenna problems, part I: some basic relations for eigenmode expansions and their relation to the singularity expansion;Baum C.E.;Interaction Note,1975