Forestry and forest products; compiled by Harold S. Betts, C. W. Boyce, Mrs. J. E. Haupt, Rufus Helphenstine, jr., Joseph Kittredge, Wilbur R. Mattoon, Alice M. Meynes, Albert H. Pierson, R. V. Reynolds, Helen Smith, W. N. Sparhook [Sparhawk], E. B. Stabler, Ansel D. Talbert, C. R. Tillotson, Raphael Zon, Joseph A. Becker, Lewis B. Flohr, and Birdella Miller.