title: Laboratory host systems for extraneous agent testing in avian live virus vaccines: problems encountered.
authors.affiliation: Lohmann Tierzucht GmbH, Veterinary Laboratory, Abschnede 64, 27472 Cuxhaven, Germany. philipp@ltz.de
authors.forename: Hans-C
authors.initials: HC
authors.lastname: Philipp
authors.forename: Ines
authors.initials: I
authors.lastname: Kolla