books.google.ru - The geometric and algebraic aspects of two-dimensional homotopy theory are both important areas of current research. Basic work on two-dimensional homotopy theory dates back to Reidemeister and Whitehead. The contributors to this book consider the current state of research beginning with introductory...http://books.google.ru/books/about/Two_Dimensional_Homotopy_and_Combinatori.html?hl=ru&id=IdRsF_mezbIC&utm_source=gb-gplus-shareTwo-Dimensional Homotopy and Combinatorial Group Theory
