TY - Acta mathematica scientia,Series A A1 - Chao Wang T1 - Periodic Solutions of a Class of Nonlinear Hill's Type Equations with Bounded Restoring Force Y1 - 2019-08-26 JF - Acta mathematica scientia, Series A JO - Acta mathematica scientia,Series A SP - 761 EP - 772 VL - 39 IS - 4 UR - http://121.43.60.238/sxwlxbA N1 - ER -