Agree with Renu, I too have downloaded many notes from this site where there were many mistakes, But I never totally relied on them, In case any doubt do cross check the accuracy of the notes with any standard book on the subject, and only consider online notes for preparation after you've gone through the subject with a standard book. So you will be able to catch any discrepencies early on and avoid confusion and waste of time. Better rely on ur own notes prepared from standard books.