Documents on the history of one of the most ancient cities of the Caucasus, Derbent, are found in many manuscripts and archives, but only a small part of them gives a complete picture of the amazing fortifications, population and features of this area. An interesting analysis of the problem is given in the article by Rizvan Huseynov, senior researcher at the Institute of Law and Human Rights of ANAS, director of the "Caucasian Historical Center" about "Mentions of the city of Derbent in various medieval sources".
The article can be read by clicking on the link.