I would like to start a thread in which we would post books and notable articles/papers by great physicists/mathematicians/scientists of the past. These could be books that you found useful for study or general education. Likewise, seminal papers and other sources are welcome. We are particularly interested in obscure gems that blow one's mind with clarity, insights, and overall quality. Let's bring those goodies to light! I will start with this: "Thermodynamics" by Enrico Fermi. I used this book after having had an undergraduate thermal physics course, and it really clarified many things and made them coherent. Thermodynamics is an illusive subject ... Fermi does it like few others can.