US patent 7040, James Radley and John W. Hunter, "Spark Arrester", issued 1850-01-22
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USDA Forest Service Technology & Development Program Manufacturer Submission Procedure for the Qualification Testing of General-purpose, Screen, and Locomotive Spark Arrester Exhaust Systems (2005)[2]
USDA Forest Service Technology & Development Program Manufacturer Submission Procedure for the Qualification of Multiposition Small Engine Spark Arrester Exhaust Systems (2001)[3]
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USDA Forest Service Technology & Development Program An Introduction to Spark Arresters - Spark Arresters and the Prevention of Wildland Fire (2003) [1]