Ebook: Classical Invariant Theory

Except for some new terms ( transvectants, Hessians, Syzygies, special Euclidean groups)
and notation ( I haven't figured out exactly what he means by A^(-T) yet, inverse transpose?),
it is a well written book that revives the ancient Hilbert
invariant theory and translates that into
modern terms. I was hooked when I realized the connection to the elliptic invariant.
It has this neat section on Gordon's method of digraphs as algebraic invariants.
I really think some of this could be made where it could be taught to undergraduates without calculus.
For me the treatment of invariants tied a lot of loose ends together.