Optical and X-ray outbursts of Be/X-ray binary system SAX J2103.5+4545 Ü. Kızıloğlu, S. Özbilgen, N. Kızıloğlu and A. Baykal A&A, 508 2 (2009) 895-900 Published online: 27 October 2009 DOI: 10.1051/0004-6361/200912638