The IBM ´golf ball´ typewriter revolutionised the 1960s office. For the first time a single machine offered interchangeable typefaces, a carbon ribbon... - SuperStock
IBM's Type Ball for typewriter. It's allows to change the character | Olx
Design Moment: IBM 'Golf Ball', 1961 – The Irish Times
IBM Selectric - Wikipedia
Phil Patton appreciates the IBM Selectric: Design Observer