If you are looking for a specific collection of "30 books" or a specific "30-page" document, these are typically found on academic sharing platforms:

His collection was not for sale. It was a legacy.

The Librarian of 30 Keys

In a small, rain-lashed town in the mountains of northern Colombia, lived a man named Keyner Ramírez Mojica. To his neighbors, he was the quiet owner of a tiny secondhand book stall. But to a secret online community, he was El Bibliotecario de los 30 — The Librarian of the 30.

Si "30" está disponible en PDF, priorice: