Schweingruber, F. H. (2007). Tree-ring measurements of Picea engelmannii (Engelmann spruce) from sample SILVER-132. PANGAEA.
Chicago-viite (17. p.)Schweingruber, Fritz Hans. Tree-ring Measurements of Picea Engelmannii (Engelmann Spruce) from Sample SILVER-132. PANGAEA, 2007.
MLA-viite (9. p.)Schweingruber, Fritz Hans. Tree-ring Measurements of Picea Engelmannii (Engelmann Spruce) from Sample SILVER-132. PANGAEA, 2007.
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