Lu, C.-J.C.-J.LuTien, M.-H.M.-H.TienCHUNG-JEN LU2020-01-132020-01-132012https://scholars.lib.ntu.edu.tw/handle/123456789/447067Pure-rotary periodic motions of a planar two-ball auto-balancer systemjournal article10.1016/j.ymssp.2012.06.0012-s2.0-84865023289https://www.scopus.com/inward/record.uri?eid=2-s2.0-84865023289&doi=10.1016%2fj.ymssp.2012.06.001&partnerID=40&md5=896ba0303739dd6cd55145cf2277e51c