I noticed there are a few books (in Russian) specific to competitive programming in e-maxx. For example, Олимпиадные задачи по программированию by Меньшиков; the CD with materials is also available and the tasks are also hosted in acmp.ru. However, the book is rather old.
Are these books actually popular in the Russian-speaking community? What about the tasks' quality? How do they compare to more modern English-language alternatives, such as pllk's book and Competitive Programming?