| astm.org | ASTM International |
| asphaltroofing.org | Asphalt Roofing Manufacturers Association |
| gaf.com | GAF Materials Corporation |
| certainteed.com | Saint-gobain Vetrotex: Glass Fiber Reinforcements For Composites |
| wsrca.com | Western States Roofing Contractors Association |
| rooftex.com | Roofing Contractors Association of Texas |
| roofonline.org | Roofonline |
| roofingcontractor.com | Rc: Roofing Contractor Magazine (now Incorporating Contractors Guide) |
| rci-online.org | Roof Consulting: The Roof Consultants Institute, Online |
| nrca.net | NRCA, The National Roofing Contractors Association |
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