Basic English Usage
Swan, Michael

Ask and Answer
Rohrauer/schönberger

Intermediate Listening
Timesaver

Smile III
Lichtenwagner, Claudia

Internet-Wörterbuch
Langenscheidt

The Art of Teaching English
Morris

English for your trip abroad
Lion, Michael

A Commercial Course
Eckersley/Kaufmann

Visual Dictionary
Merriam-Webster's

Divided Ireland
O'Donovan, Noreen