Thanks, Csantos for advise about rent the books. Can you , please, tell me more about that. I never thought about renting textbooks, but if we consider that publishers reprint any other year books just only adding a couple of pages, it is really a bad idea to buy books and spent hundreds of dollars on them. As English is a second language for you , I can advise you to consider Franklin electronic speaking dictionary (Merriam-Webster's collegiate Dictionary) It is just wonderful. I was carrying it throughout my college. You can consider models isbn 9781590744185 or ISBN 1590741749 Also, they have a thesaurus part which I used a lot. I bought them around 40 at ebay.
I'm right know in process looking for the books. Therefore, i will be considering to rent some books. I need more information on that.