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2. ASTM-F-609-79, 1984. Standard Method of Test for Static Slip Resistance of Footwear Sole, Heel, or Related Materials by Horizontal Pull Slipmeter (HPS), Annual Book of ASTM Standards. American Society for Testing and Materials, Philadelphia.
3. The actual contact area and friction properties of elastomers under frictional contact with solid surfaces;Bartenev;Rubber Chemistry and Technology,1972
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