The structure Question word do you think.....? is always translated as Как ты думаешь/вы думаете......? For example, What do you think she is doing now?-Как ты думаешь,что она сейчас делает? When do you think the train arrives?-Как ты думаешь, во сколько прибывает поезд? Where do you think I got this books from?- Как ты думаешь, откуда я взял (достал) эти книги? You can say "получил", but it sounds less natural to my ear.

Okay Mario, if you are only discussing 1 book, you can say or write "this book". If you are discussing more than 1 book, you can say or write "these books". It would help if I knew the INTENT of the question, but; as a general inquiry, your sentence; "Where do you think I got these books from?" Can be expressed as follows: "Where do you think I got these books from?" "Can you guess where I got these books from?" "Is it a mystery where these books came from?" "Where do you think I got these books?" "Isn't it interesting that nobody can figure out where I got these books?" " Can you agree that nobody could ever guess where I got these books?" .

where do you think ?

where do you think I got this books from? -- Где, ты думаешь, я получил эти книги? / где, ты думаешь, я достал/взял эти книги? ///////////// where do you get the idea that I got this books? -- Почему ты думаешь, что я получил эти книги?

Thanks Denis.