- Author: Карпов В.А.
- Language: Bulgarian-Русский
- Author: Гинина С.Ц. Платонова И.В. Усикова Р.П.
- Language: Bulgarian-Русский
- Author: Radewa Sabina.
- Language: Bulgarian-Polish
- Author: Венедиктов Г.К.
- Language: Bulgarian-Русский
- Author: Vrinat-Nikolov M. Mikhaïlova S.
- Language: Bulgarian-French
- Author: Благоева Д.
- Language: Bulgarian-Русский
- Author: Бъчваров Янко и др.
- Language: Bulgarian
