Single-sided rack equipment : Strowger automatic telephones / Automatic Telephone Manufacturing Company Ltd.
The layout of "Strowger" automatic exchanges : Strowger automatic telephones / Automatic Telephone Manufacturing Company Ltd.
The 32A selector : B.P.O. type 2,000 / Automatic Telephone Manufacturing Company Ltd.
The development of the telephone in europe / Herbert Laws Webb, M.I.E.E.; Harold Cox