Bolman has studied regional variation in douglas fir seed yields . 鲍尔曼曾研究过道格拉斯冷杉种子产量地区间的差异。
2.
Qualitative classification of softwood round timber - larches and douglas firs 圆软木的定性分类.落叶松和枞木
3.
Qualitative classification of softwood round timber . larches and douglas firs 软木圆材的定性分类.落叶松木和黄杉木
4.
On mountain slopes that receive plentiful rainfall , huge douglas firs rise in towering columns 在有充足降水的斜坡,巨大的道格拉斯枞树高耸入云。
5.
Sawn timber - appearance grading of softwoods - european spruces , firs , pines and douglas fir 锯材.软木的外观等级.欧洲云杉木松木冷杉木和花旗松
6.
Sawn timber . appearance grading of softwoods . part 1 : european spruces , firs , pines and douglas firs 锯材.软木的外观分级.第1部分:欧洲云杉冷杉松木和黄杉
7.
Qualitative classification of softwood round timber - part 3 : larches and douglas firs ; german version env 1927 - 3 : 1998 软圆木质量分级.第3部分:落叶松和花旗松
8.
Sawn timber - appearance grading of softwoods - part 1 : european spruces , firs , pines , douglas fir and larches 锯材.软木的外观分级.第1部分:欧洲云杉冷杉松木黄杉和落叶松
9.
Sawn timber - appearance grading of softwoods - part 1 : european spruces , firs , pines , douglas firs and larches including amendment 1 : 2002 ; german version en 1611 - 1 : 1999 a1 : 2002 锯材.软木的表面分级.第1部分:欧洲云杉冷杉松树