1. English Grammar in Use
by Raymond Murphy
Cambridge University Press
2. English Usage
by John Sinclair
The Univercity of Birmingam, Collins Cobuild, Прозорец

3. Английска граматика за всички
Анна Павлова, изд. Авелина
4. English Prepositions
Nauka i Izkoustvo
5. Dictionary of Idioms
Cambridge & Прозорец
6. Internet