2
Published 2008
Rectors Conference of the Republic of Bulgaria

3
Published 2017
OECD Publishing

5
by Gesemann, Gerhard
Published 1996
Peter Lang International Academic Publishing Group

8
Published 2007
Mid Yorkshire Chamber of Commerce and Industry - Branch Bulgaria

10
Published 2006
Rectors Conference of the Republic of Bulgaria

11
by Ziegerer, Penka
Published 1994
Peter Lang International Academic Publishing Group

12
by Freidhof, Gerd
Published 1980
Peter Lang International Academic Publishing Group

13
by Reinhardt, Johannes
Published 1985
Peter Lang International Academic Publishing Group

14
by Sobolev, Andrej N.
Published 1989
Peter Lang International Academic Publishing Group

16
Published 2019
OECD Publishing

18
by Sobolev, Andrej
Published 2001
Peter Lang International Academic Publishing Group