Kummer's 1844 Book in Latin about $\Bbb Z[\zeta_n]$ Kummer wrote a book in 1844 entitled "De Numeris Complexis, Qui Radicibus Unitatis Et Numeris Integris Realibus Constant" (About Complex Numbers, Which Consist Of Roots Of Unity And Real Integral Numbers), but I cannot find its online text anywhere; I can only find amazon pages like this one. I would be interested to have an online pdf version of this text which should be in the Public Domain.
 A: For the sake of not leaving this question unanswered, there is a pdf of Kummer's book available on Google books at this link. This is the same link as in my comment above.
Google books is my second shot for out-of-copyright old books like this, after a web search on the title.  After that, archive.org is worth a go.  If that fails, major university or copyright libraries may have it (e.g. the Google books copy is digitised from a physical one in Harvard) - if you can't access one of these yourself, in normal times you could ask any contacts you have to check their local library records. Any library system you have access to may be able to obtain a copy or scan of the book on an inter-library loan, but this is likely to be slower.  There are also of course sites like lib-gen.
Amazon links for things like this mostly to come from companies who make print-on-demand versions of out-of-copyright texts. There are reasons to be wary about these - first you don't know if you're really getting what they say you're getting, second the existence of a PoD version suggests that there's a free pdf out there somewhere - but in my limited experience of buying these I always got the right thing at a pretty reasonable price even if the print quality wasn't the best. Second hand book dealers sometimes carry original copies, but the prices for obscure texts like this can be high - you can find their listings on amazon or its subsidiary abebooks as well as specialist sites.
