your problem is huge because you have very short span of preparation but every thing is possible in love, war and studies. So , don't worry you can do it within a time limit.Don't purchase books right now.First of all you go to syllabus read it thoroughly then survey the past papers. when you are surveying papers ,find out topics that asked by examiner and area of focus in past papers. Enlist 25 most common and asked question. choose a topic of question and put a topic name on google search bar and search and find two or three relevant articles or essay about topic. Read the essay or you may find research articles. Read all thoroughly then make opinion whether in favor or against. Then write short notes or points that relevant to your opinion down on paper. DO this for all subjects. you will find that it is an easy task to get through papers.

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“Never leave that till tomorrow which you can do today.”
Benjamin Franklin