For copyright purposes and to avoid plagiarism, which is a problem, we cannot directly give pdfs away, but you can download within the flipbook viewer (on tablets or phone)
In addition however there is also a good solution for you, FILE BELOW (It is suggested to download 1 or 2 units at a time) There is a trick to create a pdf from the materials, please see instructions here
Hope that helps and let us know any questions at business@learnhotenglish.com