Design and performance of acoustic metamaterial structure for inlet duct noise attenuation [Online resource]Lavrentjev, Jüri; Rämmal, HansSETC 2017 : 23rd Small Engine Technology Conference “Small Engine Technology - Generating a Promising Future”, November 15-17, 2017 Jakarta, Indonesia : Final program : SAE Technical Paper2017 / 2017-32-006, p. 37 http://www.setc-jsae.com/past_docs/2017/list_of_paper.pdf Reliability study of micro-perforated elements in small engine silencer applicationRämmal, Hans; Lavrentjev, JüriSETC 2017 : 23rd Small Engine Technology Conference “Small Engine Technology - Generating a Promising Future”, November 15-17, 2017 Jakarta, Indonesia : Final program : SAE Technical Paper2017 / 2017-32-0075, p. 37 http://www.setc-jsae.com/setc2017docs/2017finalprogram/SETC2017_Final.pdf