https://arxiv.org/abs/astro-ph/0502417
[astro-ph/0502417] A XMM-Newton View of the Soft Gamma-ray Repeater SGR 1806--20: Long Term...
Abstract page for arXiv paper astro-ph/0502417: A XMM-Newton View of the Soft Gamma-ray Repeater SGR 1806--20: Long Term Variability in the pre-Super Giant...