Mary E Ramsay, Nick J Andrews, Caroline L Trotter, Edward B Kaczmarski, Elizabeth Miller
Ramsay M E, Andrews N J, Trotter C L, Kaczmarski E B, Miller E.
Herd immunity from meningococcal serogroup C conjugate vaccination in England: database analysis
BMJ 2003; 326 :365
doi:10.1136/bmj.326.7385.365