| | Assoc.prof.Nina, Yankova Level of socio-economic development and potential of districts [Текст] / Yankova Assoc.prof.Nina, Ph.D. // Economics 21 : Interuniversity journal. — Svishtov, Varna, Sofia : "Tsenov" Academic Publishing House, 2011. — Book 1. — C. 140-146. |
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