Dobado González, AntonioLópez Maroto, Antonio2023-06-202023-06-201996-02-150556-282110.1103/PhysRevD.53.2262https://hdl.handle.net/20.500.14352/58734© 1996 The American Physical Societyengjournal articlehttp://prd.aps.org/abstract/PRD/v53/i4/p2262_1http://prd.aps.org/open access53Física (Física)22 Física