Komitov, Boris. “Study on European Beech Annual Tree Ring Widths Time Series, Solar–Climatic Relationships and Solar Dynamo Regime Changes”. Current Advances in Geography, Environment and Earth Science Vol. 1 (December 11, 2021): 74–100. Accessed June 19, 2026. https://stm.bookpi.org/CAGEES-V1/article/view/5188.