RX J2133.7+5107: identification of a new long period Intermediate Polar J. M. Bonnet-Bidaud, M. Mouchet, D. de Martino, R. Silvotti and C. Motch A&A, 445 3 (2006) 1037-1040 Published online: 03 January 2006 DOI: 10.1051/0004-6361:20053303