It sounds like you're trying to track down a specific resource: (likely 1st year of ESO / Secondary, or 1st of a series) in PDF format, and you want it gratis (free).
: For many students, the cost of physical textbooks can be a barrier. Digital resources, when legally provided through school portals or libraries like the BIBLIOTECA EES N°9 9 Santillana Ciencias Naturales 1 It sounds like
Here is a step-by-step guide to getting a high-quality, legal, and often free or low-cost version of the textbook. For studying one chapter: Download the official muestra
(Use this if you are designing an app or a website download page to make the user experience seamless.) Option 3: Public Library or University Repository (Free
Searching for shows that you are a resourceful student. You want quality learning materials without spending a lot of money. That is admirable.