Products Laboratory (U.S.), Forest, and Sylvia M Lecher. 1946. Effect of Boiling for Various Periods of Time On the Strength of Joints In Birch Plywood Bonded with Urea Glue Fortified with Varying Amounts of Melamine and Resorcinol. : Madison, Wis. : U.S. Dept. of Agriculture, Forest Service, Forest Products Laboratory.