Sometimes my students ask me: Which textbook do you recommend for learning your discipline (I give lectures in two disciplines: Mechanics and Probability). Usually, I answer: Each discipline is like a sculpture, and each textbook is a photocopy of it made from the author’s point of view. For a superficial acquaintance, one good textbook may be sufficient, but if you wish to get a detailed knowledge of it, you must read a few textbooks represented various points of view.