A.  Yamada, Kitamura, D., Setoguchi, M., Matsuda, Y., Hashimoto, Y., N., M., and Fukuda, M., ?Monotropastrum humile var. humile is associated with diverse ectomycorrhizal Russulaceae fungi in Japanese forests?, Ecol. Res., vol. 23, pp. 983 - 993, 2008.