@Article{MC-12-1, author = {}, title = {封二}, journal = {数学文化}, year = {2021}, volume = {12}, number = {1}, pages = {0--0}, abstract = {}, issn = {2617-8656}, doi = {https://doi.org/2021-MC-18698}, url = {https://global-sci.com/article/89229/%E5%B0%81%E4%BA%8C} }