Lang, Birgit, Bibiana Betancur-Corredor, and David J. Russell. “Earthworms Increase Mineral Soil Nitrogen Content – a Meta-Analysis”. SOIL ORGANISMS 95, no. 1 (April 1, 2023): 1–16. Accessed April 24, 2024. https://soil-organisms.org/index.php/SO/article/view/308.