Oxford World's Classics, etc.

[Extollager]

We have a thread going on the venerable Everyman's Library. Here's a place for discussing similar series.

http://booksinwernicke.blogspot.com/2012/03/world-classics-library-within-library.html

Everyman's Library and World's Classics were by no means the only small-format book issues of their day. There was Nelson's Classics, etc. For that matter, there was Tauchnitz's series of books that were predecessors of paperbacks.

https://paperbackrevolution.wordpress.com/tauchnitz/