I am myself a friend of narrow gauge railways, and trade since nearly 20 years books to this topic from all over the world. Since I am doing this only as a hobby, there is a lack of professionalism here and there. I ask for your understanding.
The following lists of items (pdf-data) are sorted by regions, which means you may find items twice, one time under the country where the book was published and in addition by country of the described railways. Beside actual new items you can also find antiquarian titles, in new and used condition. The text for these items is lightly grayed out. The descriptions in the listings is only in German language, sorry.
For questions, please write an email to: karl.paskarb (at) schmalspurverlag.de . I will be pleased to answer you.