External Equivalent for Electric Power Distribution Networks With Radial Topology Neto, A. C. ; Rodrigues, A. B. ; Prada, R. B. ; da Guia da Silva, M. Abstract Publication: IEEE Transactions on Power Systems Pub Date: August 2008 DOI: 10.1109/TPWRS.2008.922250 Bibcode: 2008ITPSy..23..889N