Kullman, Leif. 2021. “Recently Enhanced Pine (Pinus Sylvestris L.) Regeneration and Extensive Penetration towards the Head of the Handölan Valley: Reversal of a Long-Term Retrogressional Trend – Contrasting Responses to Climate Change of Tree- and Forest Line”. Challenging Issues on Environment and Earth Science Vol. 3, April, 44-58. https://doi.org/10.9734/bpi/ciees/v3/8096D.