Theoretical study on the law of the sea in China Theoretical study on ocean law of China Theoretical study on contract law in the Chinese civil code Theoretical study of residential justice in China Theoretical study on the compilation of translatology dictionaries theoretical study of Welsh school security theory 并列题名：Theoretical study on contract law in the Chinese civil code Empirical study on the level of natural sciences research in China 并列题名：Theoretical study on ocean law of China 并列题名：Theoretical study of residential justice in China