Book recommendations for improving English

Hello, could you recommend books to help me improve my English? Since it's a foreign language for me, staying focused can be quite challenging. I'm particularly interested in books with interesting facts and lessons, and I have a keen curiosity for topics that offer guidance and valuable insights. Although I find it challenging to understand the original texts of Sherlock Holmes, I do enjoy reading stories of that nature.

Do you have any suggestions for books that include short stories?

I prefer books available in epub format for easy downloading and reading. My English level is intermediate to upper-intermediate.

Thank you for your help

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