1. Neisseria meningitidis strains with decreased susceptibility to penicillin;D, I.Van Esso; D, Fontanals; S, Uriz;J Paediatr Infect Dis,1987
2. Penicillin-resistant Neisseria meningitidis in Southern Africa;Botha, P.;Lancet,1988
3. Penicillin-insensitive meningococci in the UK;Sutcliffe, E.M.; Jones, D.M.; El-Sheikh, S.;Lancet,1988
4. An outbreak of meningococcal disease in Gloucestershire;Cartwright, K.A.V.; Stuart, J.M.; Noah, N.D.;Lancet,1986
5. Quoted by Duguid JP. Staining Methods;Cruickshank, R.,1975