M. Krüger; C. Krüger; C. Walker; H. Stockinger; A. Schüßler (2011). «Phylogenetic reference data for systematics and phylotaxonomy of arbuscular mycorrhizal fungi from phylum to species level.». New Phytologist193 (4): 970-984. PMID22150759. doi:10.1111/j.1469-8137.2011.03962.x.
Retallack, G.J.; Krull, E.S.; Thackray, G.D.; Parkinson, D. (2013). «Problematic urn-shaped fossils from a Paleoproterozoic (2.2 Ga) paleosol in South Africa». Precambrian Research235: 71-87. doi:10.1016/j.precamres.2013.05.015.
nih.gov
ncbi.nlm.nih.gov
M. Krüger; C. Krüger; C. Walker; H. Stockinger; A. Schüßler (2011). «Phylogenetic reference data for systematics and phylotaxonomy of arbuscular mycorrhizal fungi from phylum to species level.». New Phytologist193 (4): 970-984. PMID22150759. doi:10.1111/j.1469-8137.2011.03962.x.