If you’re interested in reading more about the history of punctuation, the following works stand out as being of particular merit:
- R. Bringhurst, The Elements of Typographic Style : version 3.2, Hartley and Marks, Publishers, 2008.
- The book which first got me hooked on typography: if you’re remotely interested in typography, book design or typographic characters, this is the book to get. A joy to read!
- M. B. Parkes, Pause and Effect: Punctuation in the West, University of California Press, 1993.
- M.B. Parkes’ comprehensive, magisterial and infuriating masterpiece on the development of punctuation from ancient Greece onwards. This heavyweight, scholarly tome dispenses with such niceties as readability, accessibility and pleasing design, and yet is probably the single most useful work on the origins of modern punctuation.