Source of Geometric Drawing Tut's or books

Hi,

Just getting into chip carving, I'm atracted by the geometric layouts (not
being very artistic to say the least)

Can anyone point me to tutorials or books regarding the making of patterns
i.e

compass/paper, CAD etc

I'm not after projects/plans and I have bought a couple of books, but good
as they are for learning to carve, I want to concentrate on the pattern
making methods

e.g rosettes, borders, lattice, dihedrons etc even if it containsd the
dreaded maths.

Any pointers would be appreciated.