OTU
Chen, W.; Zhang, C. K.; Cheng, Y.; Zhang, S.; Zhao, H. (2013). “A comparison of methods for clustering 16S rRNA sequences into OTUs.”. PLOS ONE 8 (8): e70837. Bibcode: 2013PLoSO...870837C. doi:10.1371/journal.pone.0070837. PMC 3742672. PMID 23967117. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3742672/.