Filtra

Russian Centre of Education (Arkhangelsk / Northwestern Federal District / Russia)
Petrolingua Ltd. (San Pietroburgo / Northwestern Federal District / Russia)
Nevsky Institute of Language & Culture (San Pietroburgo / Northwestern Federal District / Russia)
INTEX (Surgut / Ural Federal District / Russia)
Language Studio (San Pietroburgo / Northwestern Federal District / Russia)
Lenda - Center (San Pietroburgo / Northwestern Federal District / Russia)
Lingua-Seasons (Mosca / Central Federal District / Russia)