1. OIE, FAO and European Community Reference Laboratory for Newcastle Disease and Avian Influenza, Virology Department, Veterinary Laboratories Agency Weybridge, Addlestone, Surrey, UK
2. OIE, FAO and National Reference Laboratory for Newcastle Disease and Avian Influenza, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10. 35020 – Legnaro, Padova, Italy