H*V approximations - the structure of unstable algebras with applications to spaces Author: Jesper Grodal Date: Feb 1997. Status: Accepted. Pages: viii+38. Abstract: This is my 1997 Master's thesis from The University of Copenhagen. The thesis contains the results also presented in the paper The transcendence degree of the mod p cohomology of finite Postnikov systems. Moreover I give an introduction to the theorems of Quillen and Serre which the results can be seen to evolve around. I also give a complete proof of a theorem of Henn, Lannes and Schwartz about the structure of category of unstable algebras over the Steenrod algebra, which is used in proving the main results.