If you tell me which specific chapters or concepts you need (e.g., “cell signaling” or “DNA replication”), I can point you to legal, free resources in Spanish that cover the same material as De Robertis.

It looks like you’re searching for a PDF of the book by Héctor N. De Robertis and colleagues (often referred to simply as De Robertis ). This is a classic, widely used textbook in Spanish-speaking universities for introductory cell and molecular biology.