Marshall Cavendish Corporation, World and its peoples. Middle East, western Asia and northern Africa., Marshall Cavendish, 2006, p. 751, ISBN 978-0-7614-7571-2, OCLC 62282418.
«In a series of wars with Persia at the beginning of the nineteenth century, Russia gained the Azeri khanates north of the Araks River, which still forms the frontier between Azerbaijan and Iran.»