In the Wikipeadia article
http://en.wikipedia.org/wiki/Lie_coalgebra
on Lie coalgebras an author said: "... Just as the exterior algebra of vector fields on a manifold form a Lie algebra [...], the de Rham complex of differential forms on a manifold form a Lie coalgebra ...". Unfortunately the article gives no references at all.
If this is true I'm interested to learn more about that coalgebra structure on the de Rham complex of differential form and it would be great if someone knows a reference.
I'm especially interested in the interaction of that coalgebraic structure with calculus on differential forms (i.e exterior derivation, Lie derivation, insertion of vector fields ...)
Edit: As it turns out in the wiki on the exterior algebra is is said, that the wedge product and the shuffle coproduct together define a Hopf algebra and in particular the shuffle coproduct gives a coalgebra structure on the exterior algebra of a vector space.
In the light of this a reference to this Hopf algebra would be a reference of interest. But moreover it would be good to know how this Hopf algebra structure interacts with the calculus.