A, B, C are three good textbooks from the market. An author/professor translates them, taking chapter 1 from A, 2 from B, 3 from C and combining them into another textbook. The content of the new textbook is literally taken from other sources, with simple editing (cut irrelevant part that they don't teach in their class even it's in the taken chapter).
My questions are:
What is the name of this kind of textbook?
If the author of the new book is the one who makes translation and edition, then is it ethical/legal? What is the name of this action?
If the reason given is "lacking of good resources" in the country, and A, B, C are cited as references, then is this action really bad? Is there any alternative way to do?