Biographies and activity
Author: ROUSSEV IVAN
The following are among the large farm (chiftlik) owners and tenants in the region of Burgas in the XIX century: Zafeiropoulos bey( in 1869 he was the first to imported from England threshing machines), Omer bey, Tefik effendi, Suleiman bey, Mordechai S. Cohen, Halil Pasha and his successors, Demetrius T. Brakalov (in 1870 brings the first harvesting machine in Burgas driven by 15 horses), Ivan Hadjipetrov. 
 Карайотов, И., Ст. Райчевски, М. Иванов. История на Бургас. От древността до средата на XX в. Бургас, 2011, с. 117–118.