1. a Rockwool Insulation Holding, DK-2640 Hedehusene, Denmark
2. b Owens-Corning Fiberglas, Technical Center, 2790 Columbus Road, Route 16, Granville, OH 43023-1200
3. c Schuller International, Mountain Technical Center, P. O. Box 625005, Littleton, CO 80162-5005
4. d USG Corporation, Research Center, 700 North Highway 45, Libertyville, IL 60048-1296