1. A preliminary study of sound absorption using multi-layer coconut coir fibers;Nor;Electron J: Tech Acoust,2004
2. Acoustic properties of multilayer coir fibres sound absorption panel;Zulkifli;J Appl Sci,2008
3. Tamiri FM. Rekabentuk dan pengujian panel penyerap bunyi semi-aktif menggunakan bahan sabut kelapa (Design and testing of semi-active sound absorption panel using coir fiber material). Master thesis, Department of Mechanical and Materials Engineering, Faculty of Engineering, Universiti Kebangsaan Malaysia; 2005.
4. On the design of perforated facings for acoustic materials;Bolt;J Acoust Soc Am,1947
5. Absorption characteristics of acoustic material with perforated facings;Ingard;J Acoust Soc Am,1951