موارد
APA – The Engineered Wood Association
California Redwood Association
Eastern White Pine
Northeastern Lumber Manufacturers Association
Pacific Lumber Inspection Bureau
Softwood Export Council
Southeastern Lumber Manufacturers Association
Southern Cypress Manufacturers Association
Southern Forest Products Association
Southern Pine Inspection Bureau
Timber Decking Association
Redwood Inspection Service
West Coast Lumber Inspection Bureau
Western Red Cedar Lumber Association
Western Wood Products Association