A. Andreev's work - documentary biography of Ivan Vasilyevich III. Ivan Vasilyevich's contractual letters are published in the work, Moscow and Novgorod stories about Ivan Vasilyevich's campaign in Novgorod, Korostyn Treaty of Veliky Novgorod with Grand Duke Ivan Vasilyevich on Peace of 1471, Message to the Ugra Vassian Rylo, The Tale of Standing on the Ugra, Judicial code of 1497, as well as the spiritual letter of Ivan Vasilyevich, many other genuine documents of that time.