4Brogden, K A Rhoades, K R, Rimler, R B. Serologic types and physiologic characteristics of 46 avian Pas- teurelt anatipestifer cultures [J]. Avian Dis.1982 26 (4): 891-896.
5Sandhu, T. S., and H. C. Tan. Serotypes of Pasteurella anatipestifer isolates from poultry in different countries [J]. Avian Pathol. 1991, 20:233-239.
6Loh, H.,T. P. Teo, and H. C. Tan. Serotypes of Pas- teurella anatipestifer isolates from ducks in Singapore:a proposal of new serotypes [J]. Avian Pathol . 1992, 21: 453-459.
7Pathanasophon P.,Sawada T., Tanticharoenyos T et al. New serotypes of Riemerella anatipestifer isolated from ducks in Thailand[J]. Avian Path, 1995,24:195-199.
