Based upon lecture notes for a course taught by Kleinert, this monograph explains in detail how to perform perturbation expansions in quantum field theory to high orders. The authors also describe how to extract the critical properties of the theory from the resulting divergent power series. Kleinert teaches physics at the Freie U. in Berlin and Schulte-Frohlinde is a visiting scientist at Harvard. Annotation c. Book News, Inc., Portland, OR (booknews.com)