@Article{MC-4-4, author = {}, title = {封面}, journal = {数学文化}, year = {2013}, volume = {4}, number = {4}, pages = {0--0}, abstract = {}, issn = {2617-8656}, doi = {https://doi.org/2013-MC-11670}, url = {https://global-sci.com/article/89898/%E5%B0%81%E9%9D%A2} }