MLA

Wilson, T. R. C. (Thomas Randall Carson), 1884-, and Forest Products Laboratory (U.S.). Guide to the Grading of Structural Timbers and the Determination of Working Stresses : Supplement to U.s. Department of Agriculture Miscellaneous Publication 185. : Madison, Wis. : U.S. Dept. of Agriculture, Forest Service, Forest Products Laboratory, 1940.