I went to the library to return the book, but the librarian didn't brush it. It was later discovered that 3.8 yuan was overdue. Can you make it clear? Shanghai Huangpu District Library, please reply online. If you can provide relevant certificates to prove that you have returned the books to the library before, if so, it will be difficult to collect these certificates. I suggest you negotiate directly with the librarian, and you can record it during the negotiation. Maybe there will be something beneficial in the negotiation process, but personally, I think it is best to let the librarian return the book. If you have difficulties, you can complain to the librarian. I don't know if this 3.8 or overdue return means anything to you. That's just me.