Kreykenbohm, I., F. Fürst, L. Barrágan, J. Wilms, R. E. Rothschild, S. Suchy, and K. Pottschmidt. “4U 1909+07: A Hidden Pearl”. Acta Polytechnica 51, no. 1 (January 1, 2011). Accessed May 4, 2024. https://ojs.cvut.cz/ojs/index.php/ap/article/view/1326.