J. H. Pollreisz, C. L. Kelling, B. W. Brodersen, L. J. Perino, V. L. Cooper, and A. R. Doster, “Potentiation of bovine respiratory syncytial virus infection in calves by bovine viral diarrhea virus”, Bov. pract., vol. 1997, no. 31.1, pp. 32–38, Jan. 1997.