- Author: Dr.-Ing. Nikolay Ivanov Kolev (auth.)
- Language: German
- Year: 1986
- Author: Nikolay Ivanov Kolev (auth.)
- Language: English
- Year: 2012
- Author: Nikolay Ivanov Kolev (auth.)
- Language: English
- Year: 2012
- Author: Nikolay Ivanov Kolev (auth.)
- Language: English
- Year: 2012
- Author: Nikolay Ivanov Kolev (auth.)
- Language: English
- Year: 2012
- Author: Nikolay Ivanov Kolev (auth.)
- Language: English
- Year: 2012
- Author: Nikolay I. Kolev PhD. DrSc. (auth.)
- Language: English
- Year: 2007
- Author: Nikolay I. Kolev PhD. DrSc (auth.)
- Language: English
- Year: 2007
- Author: Dr.-Ing. habil. Nikolay I. Kolev (auth.)
- Language: English
- Year: 2005
- Author: Dr.-Ing. habil. Nikolay I. Kolev (auth.)
- Language: English
- Year: 2005