Localized states of acoustic waves in three-dimensional periodic composites with point defects Fugen Wu, Huilin Zhong, Shao Zhong, Zhengyou Liu and Youyan Liu Eur. Phys. J. B, 34 3 (2003) 265-268 Published online: 11 August 2003 DOI: 10.1140/epjb/e2003-00220-6