1A. B?tner,B. Str,bygaard,K. J. S?rensen,P. Have,K. G. Madsen,E. S. Madsen,S. Alex,ers.Appearance of acute PRRS-like symptoms in sow herds after vaccination with a modified live PRRS vaccine. Veterinary Record . 1997
2Schagemann G,Wilms-Schulze KA.Safety and efficacy of Ingelval PRRS MLV in sows all stages of reproduc tion. PRRS&Aujeszkys; Disease . 1999