Mutations in the H7 HA and PB1 genes of avian influenza a viruses increase viral pathogenicity and contact transmission in guinea pigs oleh Carola Dreier, Patricia Resa-Infante, Swantje Thiele, Stephanie Stanelle-Bertram, Kerstin Walendy-Gnirß, Thomas Speiseder, Annette Preuss, Zacharias Müller, Hans-Dieter Klenk, Jürgen Stech, Gülsah Gabriel