Publisher： 国家哲学社会科学学术期刊数据库

E-ISSN： 1007-6875|38|6|107-111

ISSN： 1007-6875

Source： 河北地质大学学报, Vol.38, Iss.6, 2015-01, pp. : 107-111

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next