"Development of minimum standards for hardwoods used in producing underground coal mine timbers."; "Timson, Floyd G."; "Hardwoods.", "Mine timbering."; "Timson, Floyd G."; "1978"; "

Serial issue. Issued as: Forest Service research note, NE-261.

"; ""; "P19625"; "pec"; "Hardwoods.", "Mine timbering."; "14256"; .