Could you share some book names to learn modeling with math?

I feel it's really hard for me to figure out how to build curves etc. with jscad. Actually, I can only build things with primitives and boolean operations. Are there any good books for this topic? I tried to learn from the jscad source code, but they are some kind of math which I don't know where to start.

@crysislinux another very good area for some nice documentation.
Currently, the 2D curves are based on Bezier curves. And the IO libraries convert various curve definitions into bezier curve definitions.
SVG paths can define bezier curves as well.
You'll find lots of online tutorials on how to create bezier curves. And hopefully, you will be able to apply some of those examples within JSCAD.
P.S. 3D bezier curves are called NURBS.

That is a too broad aproach. I myself started first by creating some 2d points into a polygon and them extruding with jscad. 2D space is tricky enough, and directly making some 3D shapes with math is so much more complicated at least to me.
I have created a small utility for myself to create 2D shapes by creating the basic shape with points and with some builtin utility to have sections curved, so at first I reason about the shape I want to create in simple but more rough shape and then tweak it.
Maybe if you start with something specific you want to create I could maybe have some ideas to where you could find helpful info ... and suggest how to attack the problem.
I prefer to learn that way, find something concrete to make and see how to do it and learn missing pieces.