Editing Calculator (section)

==Further reading==
* {{US patent|2668661}} – ''Complex computer'' – [[G. R. Stibitz]], [[Bell Laboratories]], 1954 (filed 1941, refiled 1944), electromechanical (relay) device that could calculate complex numbers, record, and print results.
* {{US patent|3819921}} – ''Miniature electronic calculator'' – [[Jack Kilby|J. S. Kilby]], [[Texas Instruments]], 1974 (originally filed 1967), handheld ({{convert|45|oz|kg}}) battery operated electronic device with thermal printer
* {{US patent|4001566}} – ''Floating Point Calculator With RAM Shift Register'' – 1977 (originally filed GB March 1971, US July 1971), very early single chip calculator claim.
* {{US patent|5623433}} – ''Extended Numerical Keyboard with Structured Data-Entry Capability'' – [[Jaime Redin|J. H. Redin]], 1997 (originally filed 1996), Usage of Verbal Numerals as a way to enter a number.
* [http://ep.espacenet.com European Patent Office Database] – Many patents about mechanical calculators are in classifications G06C15/04, G06C15/06, G06G3/02, G06G3/04
* ''Collectors Guide to Pocket Calculators''. by Guy Ball and Bruce Flamm, 1997, {{isbn|1-888840-14-5}} – includes an extensive history of early pocket calculators and highlights over 1,500 different models from the early 1970s. Book still in print.
* {{cite book |title=Calculators: A Categorized Compilation of References. Supplement 1. |author-last=Suydam |author-first=Marilyn N. |publisher=Calculator Information Center, [[Ohio State University]] |publication-place=Columbus, Ohio, US |date=December 1980 |id=ED199087. SE034434 |url=https://files.eric.ed.gov/fulltext/ED199087.pdf |access-date=2022-10-16 |url-status=live |archive-url=https://web.archive.org/web/20210919201034/https://files.eric.ed.gov/fulltext/ED199087.pdf |archive-date=2021-09-19}} (64 pages)