David Paul's topic-based course for intermediate and upper intermediate students that prepares students to break through to an advanced level. Topics covered: Friends, Free Time, The Past, The Family,
A good grasp of grammar enables the foreign-language learner to build skill and confidence in communication. Here's the "ultimate," painless way for intermediate and advanced learners to bru
A practical guide to Cryptography and its use in the Internet and other communication networks.This overview takes the reader through basic issues and on to more advanced concepts, to cover all levels
