People Jesús Martín Martín chmm@gugu.usal.es Fernando Atrio Barandela atrio@astro.usal.es Luis Herrera Cometta lherrera@gugu.usal.es Eduardo Ruiz Carrero eruiz@gugu.usal.es Angelita Calvo
	Address Física Teórica Facultad de Ciencias 37008 Salamanca, Spain fax: 34 - 23 - 29 45 84 phn: 34 - 23 - 29 44 37

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Spanish Relativity Meeting. Salamanca, September 22-25, 1998.