MLA

Cheng, Shun, and Forest Products Laboratory (U.S.). Supplement to Torsion of Sandwich Panels of Trapezoidal, Triangular, and Rectangular Cross Sections : Derivation of Differential Equation and Its Application to Rectangular Panels with Loads Applied At Corners. : Madison, Wis. : U.S. Dept. of Agriculture, Forest Service, Forest Products Laboratory, 1960.