This book contains an extensive description of most of the office machines that were available in 1921. The first section is about typewriters, the second about calculators, then bookkeeping machines, duplicators, clocks, safes, and other machines. I have scanned the section on calculators and this is available at the links above.

This book is a dictionary of terms related to the office. This includes various brand names of office machines, such as calculators and adding machines. Unfortunately there are virtually no illustrations at all.

This book lists the various machines and tools that were available for the office. It has many photos and illustrations. Its chapter on calculators includes some rare machines of the time such as the Stima 4 and the Dacometer 9. I have not found any copyright year, but other sources claim it was published in 1948.

This book provides a history of adding machines, with many pictures of machines from Europe and the USA. Note that it does not include calculators. At the end it has a time line. There is no copyright year in the book, but other sources claim it was published in 1953.

This is a Russian popular science book about calculating machines. It starts off with the Russian father of the calculator, Pafnuty Chebyshev. It includes descriptions of several types of mechanism, from pinwheel to Mercedes-Euklid, and then leads on to electronic computers.

This book discusses administrative processes and the many tools to expedite them. There is a short section on calculators which explains and illustrates various types of calculator without explicitly mentioning specific brands. On one set of pages there are examples of different print reproduction methods glued in. I have not found any copyright year, but other sources claim it was published in 1959.

This book describes in detail the components and workings of electronic calculators and computers. Unfortunately it does not describe the history, so makes no mention of mechanical calculation.

This book ostensibly covers the history of the typewriter and calculator industry in Germany, but it is basically only about Olympia and Brunsviga. It contains many photos from the Olympia production line.

In-depth description of the stepped reckoner that Gottfried Wilhelm Leibniz devised.

This is a broad history of the office, from the ancients to now. It only briefly mentions calculators, and notably has an illustration of Frank Baldwin's pinwheel calculator but wrongly describes it as an Addressograph machine.

This book discusses various office machine that were manufactured in Berlin. Each chapter is by a different author and tackles a different subject, ranging from typewriters, to calculators, to copiers.

This is the book that accompanied a calculator exhibition. The first part of the book gives a history of the calculator, and the second part lists the various exhibits that were shown.

This gorgeous book shows a large number of calculators, all beautifully photographed. The short descriptions include an indication of its rarity and value. Note however that these are very subjective, based on the author's opinion, and don't always match my own experience.

This book is a special publication for the magazines "Schreibmaschinen- und Bureau-Zeitung" and "Historische Bürowelt". It shows adverts for office machines through the ages. It mostly concentrates on typewriter ads, but there are a few calculators too.

This excellent book contains various detailed articles, each on a different brand of calculator. They are accompanied with many photographs and illustrations.