Hansbrough, J. R. (John Raymond), 1903-1990, 1907-1991 Englerth, United States. Division of Forest Pathology, and Forest Products Laboratory (U.S.). 1944. The Significance of the Discolorations In Aircraft Lumber : Sitka Spruce. : New Haven, Conn. ; Portland, Or. : United States Dept. of Agriculture, Agricultural Research Administration, Bureau of Plant Industry, Soils, and Agricultural Engineering, Division of Forest Pathology, in cooperation with the Forest Products Laboratory, Forest Service, Madison, Wis..