[1]张金清.Banach空间中非线性微分方程周期边值问题的极值解[J].济南大学学报,1999,{4}(02):10-15.

Zhang Jinqing. EXTREMAL SOLUTIONS OF PERIODIC BOUNDARY VALUE PROBLEM FOR NONLINEAR DIFFERENTIAL EQUATIONS IN BANACH SPACES[J]. Journal of University of Jinan(Social Science Edition), 1999,(2).

[1]张金清.Banach空间中非线性微分方程周期边值问题的极值解[J].济南大学学报,1999,{4}(02):10-15. DOI：

Zhang Jinqing. EXTREMAL SOLUTIONS OF PERIODIC BOUNDARY VALUE PROBLEM FOR NONLINEAR DIFFERENTIAL EQUATIONS IN BANACH SPACES[J]. Journal of University of Jinan(Social Science Edition), 1999,(2). DOI：