If you're looking for a free or low-cost alternative, you may consider:

Textbooks are copyrighted material. Downloading or distributing a PDF without the publisher's permission is a violation of copyright law. While it is unlikely a student will be sued for downloading one file, the sites hosting them are frequently shut down, leaving you with a broken link halfway through the semester.

For students, researchers, and business professionals, by Donald R. Cooper and Pamela S. Schindler is often considered the "bible" of research textbooks. It covers everything from identifying research problems to data analysis and reporting.

The 14th edition has received positive reviews for its:

Many "free PDF" sites are fronts for malware. Downloading a file can lead to ransomware or keyloggers being installed on your device.