Galois Cohomology
This is an updated English translation of Cohomologie Galoisienne, published more than 30 years ago as one of the first Lecture Notes in Mathematics. It incl... »

Complex Semisimple Lie Algebras
These notes give the basic theory of semisimple lie algebras over the complex numbers including the basic classification theorem. The author begins with a su... »

Trees
These notes on groups acting on trees have influenced the development of many areas of mathematics, such as the theory of ends of discrete groups. The author... »