Пенский, О. Г.     The international cooperation of of the Faculty of Mathematics and Mechanics of the Perm State University in 2008 and its future prospects / О. Г. Пенский, В. И. Яковлев // European Journal of Natural History. - 2009. - № 5. - С. 59 Доп.точки доступа: Яковлев, В. И.