AST (Russian: АСТ) is one of the largest book publishing companies in Russia. AST and its rival Eksmo together publish approximately 30% of all Russian books. The company is headed by Oleg Bartenev (Олег Бартенев). It owns a bookstores chain "Bukva" (Russian: Буква, lit. A Letter). Among AST partners are publishing companies Astrel, Zebra E, Molodaya Gvardiya, CenterCom, bookstores Moscow and Biblio Globus and online shops, such as Ozon.ru. In 2008 AST purchased Avanta+. It also owns comic book and manga publisher Comics Factory. The company was established in 1990 by Alexei Gertsev, Sergei Derevianko and Tatiana Derevianko as "Creative Cooperative Association AST" (Russian: Творческое кооперативное объединение «АСТ»). AST is an abbreviation meaning Alexei-Sergei-Tatiana. In 1993 the company was divided into AST itself, headed by Alexei Gertsev, and AST-PRESS.