Books in this series highlight some of the most interesting works presented at symposia sponsored by the St. Petersburg Mathematical Society. Aimed at researchers in number theory, field theory, and algebraic geometry, the present volume deals primarily with aspects of the theory of higher local fields and other types of complete discretely valuated fields. Most of the papers require background in local class field theory and algebraic $K$-theory; however, two of them, ``Unit Fractions'' and ``Collections of Multiple Sums'', would be accessible to undergraduates.