Expired question
"Teach Yourself (Languages)" or "Colloquial (languages)"?

I just found 2 good websites (see below) by chance, to my surprise, one series of course books (Teach Yourself) actually contains 63 kinds of languages, and it involves much more languages than "Take Off In" that published by Oxford bookshop. I even found some uncommon books such as "Gulf Arabic", "Modern Persian", "Modern Hebrew", "New Testament Greek", & so on. Besides, the other series (Colloquial) also has many kinds of languages. But I don't want to buy from both of them, then which series is better? 【Teach Yourself (Languages): http://www.hoddereducation.co.uk/RVEd29f61b1267444b0b231be763d547941,,.aspx
Colloquial (languages): http://www.routledgelanguages.com/books/browse】