Retrieved February 7, 2015. ↑ Peter Foster, "US female hostage held by Isil is dead, confirms Obama," The Telegraph, 10 Feb 2015 ↑ "Kayla Mueller, American ISIL hostage, is dead,", Al Jazeera America, February 10, 2015 ↑ Rukmini Callimachi, "Death of Kayla Mueller, ISIS Hostage, Confirmed by Family and White House,", New York Times, FEB.