Products Laboratory: [Research report] 1553-B, 1560, 1570-71, 1639, R1643, R1650, 1662-2, R1669, R1674. 1553-B. Buckling of stiffened flat plywood plates in compression, single stiffener parallel to stress; [by C. B. Smith, L. A. Ringelstetter, and C. B. Norris].