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Oak's online GRE tests and mixed practice are so good that you don't need to refer to anything else. Their vocabulary app is superb and it helped me master the GRE word list.
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The topic-wise GRE videos were extremely engaging. The videos are not very long, and I found them very useful. The best part I liked about Oak's GRE prep was that after watching a video, I could immediately attempt practice questions for the specific topic. The questions had detailed explanations and were very helpful. I am glad I bought Oak's Self-Prep and would recommend it to anyone looking for bundled online GRE prep at an affordable price.
Avinash Jadhav

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Quantitative Reasoning Introductory Lecture
Verbal Reasoning Introductory Lecture