Downloading copyrighted materials without payment harms the authors, editors, and publishers who spent years developing high-quality language learning resources. It also means you miss out on:
Difusión often releases "Freemium" versions of their textbooks to give students a preview. These are 100% legal and free. aula internacional plus 1 pdf download link
If you are looking for the full content, here are the legal avenues to explore: aula internacional plus 1 pdf download link
If you're a student or educator, contact your school/university. They may offer access to digital copies through: aula internacional plus 1 pdf download link