mechanical calculator Museum of Design in Plastics

German Design 1949–1989: Two Countries, One History: 9783945852446: Kries, Mateo, Geisler, Thomas A., Nemecková, Klara, Pinner, Erika, Gronert, Siegfried, Castillo, Greg, Betts, Paul, Eisele, Petra: Books

Mario Bellini, Divisumma 18 (1973)

ET44 calculator

Mechanical calculator - Wikipedia

Little Professor' electronic calculator, 1980

National Museum of American History

Mechanical calculator - Wikipedia

Curta Calculators ~ Vintage Mechanical Calculators - HubPages

Plastics Museum

Mechanical Calculator Science Museum Group Collection

ET 66 calculator Museum of Design in Plastics

Vintage Round Plastic Mechanical Calculator, Manual Addition and Subtraction, Mathematic Machine, Patented DBGM