Variable gamma-ray emission from the Be/X-ray transient A0535+26? G. E. Romero, M. M. Kaufman Bernadó, J. A. Combi and D. F. Torres A&A, 376 2 (2001) 599-605 Published online: 15 September 2001 DOI: 10.1051/0004-6361:20011044