The layout of "Strowger" automatic exchanges : Strowger automatic telephones / Automatic Telephone Manufacturing Company Ltd.
Some maintenance features of "Strowger" automatic telephone systems : Strowger automatic telephones / Automatic Telephone Manufacturing Company Ltd.
The development of the telephone in europe / Herbert Laws Webb, M.I.E.E.; Harold Cox
Rede digital com integração de serviços / Telecom Portugal; Direcção Comercial