edited by Ya G Sinai (Landau Inst.)

This volume consists of very high quality articles which not only give a very good account of this field in the Soviet Union, but also provide stimulating materials for researchers working on this topic.

• On the Relations Among Various Entropy Characteristics of Dynamical Systems (E I Dinaburg)
• On Structurally Unstable Attracting Limit Sets of Lorenz Attractor Type (V S Afraimovich et al.)
• Dimensional Type Characteristics for Invariant Sets of Dynamical Systems (Y B Pesin)
• Dynamical Systems with Elastic Relations (Y G Sinai)
• Ergodic Properties of Dispersing Billiards (Y G Sinai)
• The Existence of Caustics for a Billiard Problem in a Convex Domain (V F Lasutkin)
• On the Ergodic Properties of Nowhere Dispersing Billiards (L A Bunimovich)
• Structure of Transversal Leaves in Multidimensional Semidispersing Billiards (N I Chernov)
• and other papers