Sustainable development goals 2030: Challenges for South and Eastern European countries and the Black sea region : proceedings of the 15th international conference of ADECU, organized on the occasion of 100th anniversary of the University of National and Worls Economy, September 26-27, 2019, Sofia, Bulgaria / editors Valentin Goev, Grigoris Zarotiadis . Thessaloniki :  ASECU , 2019 . 470 s . ISBN 978-619-232-257-1 .