Personally, I think it is most important not to buy more vocabulary books, but if possible, buy Balang with an English explanation. Some of them have English explanations, and you have an advantage when you do the questions. If you can't find Balang in the bookstore, go online. I remember a friend found the electronic version online before, but now I can't find it. Look online or ask others what you should do.

Memorizing words and explaining them in English are really the best. It's painful to recite, but it's much easier when you do the questions, and you can recite them from the core.

The biggest difference between word books is that the words in the exercise questions are almost the same. It is really important to remember honestly that you don't have to find one, or that there are classified words instead of alphabetical ones. I think it's easier to remember, but it depends on you personally ~)