The Azerbaijan National Academy of Sciences, the main state research organisation in Azerbaijan is locating in Baku as well. Moreover, Baku has numerous libraries, many of which contain vast collections of historic documents from the Roman, Byzantine, Ottoman and Soviet periods, as well as from other civilisations of the past. The most important libraries in terms of historic document collections include the Nizami Museum of Azerbaijan Literature, the National Library of Azerbaijan, the Mirza Alakbar Central Library, the Samad Vurgun Library and Baku Presidential Library.