TY - STD TI - Yersinia pestis - etiologic agent of plague. ID - ref1 ER - TY - STD TI - Nature , [http://www.nature.com] UR - http://www.nature.com ID - ref2 ER - TY - STD TI - The Sanger Centre , [http://www.sanger.ac.uk] UR - http://www.sanger.ac.uk ID - ref3 ER - TY - STD TI - Y. pestis genome , [http://www.sanger.ac.uk/Projects/Y_pestis/] UR - http://www.sanger.ac.uk/Projects/Y_pestis/ ID - ref4 ER -