Are "Al-Mustafa Electronic Library" and "nyitgroup.com" considered reliable websites for downloading Islamic books and applications, and if not, should one refrain from reading books downloaded from them?

Electronic books often do not differ, but the possibility of tampering with their content is plausible, albeit rare. Therefore, it is preferable to download Islamic encyclopedias from reliable Sunni websites such as IslamWeb, Dorar.net, Harf Encyclopedia, and also Al-Maktaba Al-Shamilah, provided that the books are uploaded by the site administrators and not by users.