Run a bit like this:
gutengrep "\?$" *.txt --cache --sort
multimarkdown output.txt > output.html
multimarkdown output-sort.txt > output-sort.html
Uses https://github.com/hugovk/gutengrep and 600 books from Project Gutenberg's August 2003 CD http://www.gutenberg.org/wiki/Gutenberg:The_CD_and_DVD_Project
Inspired by SpringerLink: A Novel? dariusk/NaNoGenMo-2014#129