Another angle is to mention academic resources like JSTOR, Google Scholar, or university databases where students can access parts of the textbook or related research papers, though they might need institutional access for that.
Finally, I need to ensure the response is helpful without encouraging illegal activity. Emphasize the importance of respecting copyright while guiding them towards legitimate sources. Maybe also mention the possibility of purchasing used copies, renting, or using e-books if available.
It's also possible that the user is using Spanish as their primary language and needs the book in Spanish. In that case, I should confirm if there's a legitimate Spanish edition available and provide information on how to obtain it legally. If not, suggest other bilingual resources or study materials.