Avoid random torrent sites. Try these archives:
If you search for "Gramatica Portuguesa Jose Maria Relvas pdf" on generic search engines, you will find chaos. You will find scanned copies missing pages 34 through 41. You will find OCR (Optical Character Recognition) files where the letter 's' looks like an 'f'. You will find watermarked copies from libraries.
The specific keyword "fixed" and the number "11" refer to a specific digital lineage of this file.
The "11 fixed" version refers to a community-sourced restoration project (circa 2015-2018) by a private group of Portuguese linguistics students on a now-defunct forum. They systematically corrected all 11 flaws.
Thus, when a user searches for "gramatica portuguesa jose maria relvas pdf 11 fixed", they are explicitly asking for this rare, corrected, high-quality digital version.
Relvas is famous for his precise rules on where to place object pronouns. The fixed version preserves the critical side-notes that many scans crop out.