Spread of Influenza Virus A (H5N1) Clade 2.3.2.1 to Bulgaria in Common Buzzards. - Marinova-Petkova, Atanaska; Georgiev, Georgi; Seiler, Patrick; Darnell, Daniel; Franks, John; Krauss, Scott; Webby, Richard J.; Webster, Robert G. (Emerging Infectious Diseases, 2012)