i think study material is better for Ethics. Go through the study material Thoroughly. understand the topic. and represent in the exam what u have understood.
Learn up all the answers to the questions asked in the examinations since 2007 from the suggested answers. Then learn all the answers from the RTP. That's sufficient to cover up everything...still if there's something left, refer to the study material. Study Material, Scanner and RTP - These 3 things are more than enough for any subject.