Here are some reliable avenues for Bengali Jain books and publications:

• Jain Bhawan (Kolkata) publications: A long-standing center for Jain studies and Bengali Jain publications, with journals and books in Bengali, Hindi, and English. Their publication division has updated to ISBN/ISSN in recent years. You can explore their Bengali materials through their publishing activities.

• Jain Vishva Bharati (JVB) literature: A major Jain literature publisher whose catalogue includes Bengali titles among many languages. They publish a wide range of Jain texts, study guides, and translations in multiple languages, including Bengali.

• Jain World Bengali materials: An online portal hosting Bengali Jain writings and translations, part of a global network of Jain literature resources.

If you’re looking for Bengali Jain books, start with the above organizations as primary publishers and distributors, and check their catalogues for Bengali titles, translations, and study aids.