Ortiz-León, G., L. F. Rodríguez, and M. Tapia. “Extended Non-Thermal Emission Possibly Associated With Cyg OB2 #5”. Revista Mexicana De Astronomía Y Astrofísica, vol. 48, no. 1, Apr. 2012, pp. 85-93, https://revistas.unam.mx/index.php/revmexaa/article/view/31416.