The online store or library at www.pdfsu.online called PDFSU-Book Library is untrustworthy. This is because the website has fake Facebook comments. Try clicking on comments and you will notice that they will not take you to Facebook's website. And, based on the website's copyright disclaimer, it does not store their ebooks or files on their servers, it instead, has external links to ebooks or files from other websites.
Therefore, if they do not own the ebooks or files, why should we pay for membership?
The Online Book Store or Library - www.pdfsu.online
PDFSU-Book Library
Contact Email: pdfreadbiz@gmail.com
This is PDFSU-Book Library's disclaimer, which states they do not own or have rights to the ebooks or files they display on their website:
Copyright Disclaimer: This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.
Here are the fake Facebook comments on their website:
