Арифмометры и калькуляторы. Расположение 10-клавишной цифровой секции клавиатуры
Название (англ.):
Adding machines and calculating machines; Numeric section of ten-key keyboards
Описание (англ.):
Deals with composition and layout of ten-key keyboards for adding and calculating machines as well as the shape of keys, the slope of keyboard plane, the maximum key stroke and the spacing of keys. Applies only to numerical keys constituting ten-key keybords.