SE307141B
(https= )
1968-12-23
GB320104A
(https= )
US2424359A
(en )
1947-07-22
Adding machine
US2087182A
(en )
1937-07-13
Listing adding machine
US3592313A
(en )
1971-07-13
Encoding keyboard having dual-output shift key
GB474938A
(https= )
US2055623A
(en )
1936-09-29
Calculating machine
GB1122887A
(en )
1968-08-07
A data entry machine
GB642090A
(en )
1950-08-30
Keyboard impulse transmitter for step-by-step printing telegraph
GB394999A
(https= )
US2369574A
(en )
1945-02-13
Locking mechanism for typewriting
GB852822A
(https= )
GB373131A
(https= )
SU101485A1
(ru )
1954-11-30
Клавиатура стартстопного рулонного телеграфного аппарата
GB545438A
(https= )
GB487494A
(https= )
GB191027151A
(en )
1911-09-28
Improvements in Calculating Machines.
GB672771A
(https= )
GB420807A
(https= )
1900-01-01
GB368311A
(https= )
GB438369A
(https= )
GB464746A
(https= )
GB600446A
(https= )
GB190518341A
(en )
1906-07-05
Combined Typewriting and Adding Machine.
GB401904A
(https= )