1. F. P. Doyle, J. H. Nayler, H. Smith, Improvements in or relating to penicillin derivatives, Beecham Research Laboratories Limited (UK) (1958) Patent GB873049.
2. F. P. Doyle, J. H. Nayler, H. Smith, H. Penicillins, Beecham Research Laboratories Limited (UK), (1960) Patent GB902703.
3. Pharmacology and chemotherapy of ampicillin -A new broad‐spectrum penicillin;Acred;Brit. J. Pharmacol. Chemother.,1962
4. Cover stories: a rising drug industry the pharmaceutical golden era: 1930 – 60;Daemmerich;Chem. Eng. News,2005
5. History of antimicrobial agents and resistant bacteria;Saga;Japan Med. Assoc. J.,2009