New Total English Upper-Intermediate Student's Book - Scribd
While the allure of a free PDF is strong, remember that language learning is an active process. A static PDF on a hard drive teaches nothing. Whether you buy the physical book, rent the eBook, or (legally) source a PDF, the value comes from interaction.
Having the digital file is only half the battle. Most people download a PDF, store it in a folder, and forget it. Here is a 4-week study plan to actually use the New Total English PDF.