Hα observations of the γ-ray-emitting Be/X-ray binary LSI+61°303: orbital modulation, disk truncation, and long-term variabilityR. Zamanov, K. Stoyanov, J. Martí, N. A. Tomov, G. Belcheva, P. L. Luque-Escamilla and G. LatevA&A, 559 (2013) A87DOI: https://doi.org/10.1051/0004-6361/201321991