R. Vassilev
Sociology in Bulgaria
Publishing House of the Bulgaria, 1970
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The cultural development of Bulgaria
Foreign Language Press, 1959
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Popov, Kostadin
Cultural policy in Bulgaria
Unesco Press, 1981
 Buku Teks
Profil negara Eropa: Bulgaria
Jurnal Kajian Wilayah Eropah, I (2) Mei 2005: 115-139,
 Artikel Jurnal
Simsir, Bilal N.
The truks of Bulgaria (1878-1985)
K. Rustem & Brother, 1988
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