他著作广泛，有关于各年代效率问题的，有关于最优税收的，还有用一种实用的方式表述有关社会保障方案的。
He has written extensively on efficiency across generations and on optimal taxation, and in an applied fashion on issues related to social security programmes.
第二十条权利要求书应当说明发明或者实用新型的技术特征，清楚、简要地表述请求保护的范围。
Article 20 the claims shall define clearly and concisely the matter for which protection is sought in terms of the technical features of the invention or utility model.
第二十条权利要求书应当说明发明或者实用新型的技术特征，清楚、简要地表述请求保护的范围。
Rule 20 The claims shall define clearly and concisely the matter for which protection is sought in terms of the technical features of the invention or utility model.
第二十条权利要求书应当说明发明或者实用新型的技术特征，清楚、简要地表述请求保护的范围。
Article 20 the patent claim shall state the technical features of the invention or utility model, and define clearly and concisely the scope of the requested protection.
第二十条权利要求书应当说明发明或者实用新型的技术特征，清楚、简要地表述请求保护的范围。
Article20 the patent claim shall state the technical features of the invention or utility model, and define clearly and concisely the scope of the requested protection.
第二十条权利要求书应当说明发明或者实用新型的技术特征，清楚、简要地表述请求保护的范围。
Article20 the patent claim shall state the technical features of the invention or utility model, and define clearly and concisely the scope of the requested protection.
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