1. Acentech, BNSF rail corridor soundwall noise study report, Report No. 255, Anaheim, CA, 2001.
2. Woodward-Clyde, Final Report Orangethorpe/Esperanza railroad corridor noise and vibration study, Anaheim, CA, 1996.
3. International Perforators Association, Designers, Specifiers and Buyers Handbook for Perforated Metals, International Perforators Association, 1993.
4. T.J. Schulz, Acoustical Uses for Perforated Metals: Principles and Application, International Perforators Association, 1986.
5. Federal Transit Administration, Transit noise and vibration assessment, DOT-T-94-16, Washington, DC, 1995.