Multivariate Analysis as a Method to Evaluate Antigenic Relationships between Bovine Viral Diarrhea Virus 1b Isolates and Vaccine Strains oleh Shollie M. Falkenberg, Hao Ma, Eduardo Casas, Rohana P. Dassanayake, Michael W. Bolton, Gage Raithel, Scott Silvis, John D. Neill, Paul H. Walz