In this chance, I am going to tell you, particularly all mathematics educators, about what kind of books that you need, or have to read. There are a lot of books these days, but we have to be smart enough to chose what the most important to read among them. Furthermore, there are several books that you have to pay to get it. There is no other choice. But, in the other side, there are several mathematics teachers or students that do not have enough budget to deal with. So, based upon this fact, I was searching on the internet and finally found the links for several important books for mathematics educators. The links are provided by the other people, not me. So, I am very happy that he/she makes education even better by providing e-books for free.
Then, I make a list and give a short explanation about the books either taken from the web or from the book itself. You can also download it through the links for free. Here they are.