To help you prepare for the written tests, we suggest that you look at some of the books recommended for GCSE or IGCSE candidates. The following list is not exhaustive, but all are textbooks recommended for our own students. Links are provided to Amazon for your convenience.

Mathematics
IGCSE Mathematics
by Chris Pearce

Those applying for Higher Level Mathematics would certainly benefit from studying:
Additional Mathematics for OCR
by Val Hanrahan

Biology
Longman Biology for IGCSE
by P Bradfield, S Potter

Chemistry
IGCSE Chemistry
by B. Earl, L.D.R. Wilford

Physics
Edexcel IGCSE Physics
by B Arnold, S Woolley, P Johnson

Design and Technology
The Essentials of GCSE Design and Technology: Resistant Materials
by Brian Russell (Editor)

The Essentials of GCSE Design & Technology: Product Design
by Brian Russell

Economics
Economics for Dummies
by Peter Antonioni, Sean Masaki Flynn

Those taking the Economics Higher Level test may wish to have a look at:
Thinking Skills
by John Butterworth and Geoff Thwaites

Psychology
Letts Revise GCSE Psychology
by Cara Flanagan

Philosophy
What Does it All Mean?
by Thomas Nagel