^Cavalier-Smith, T (2002). "The neomuran origin of archaebacteria, the negibacterial root of the universal tree and bacterial megaclassification". International journal of systematic and evolutionary microbiology 52 (Pt 1): 7–76.
^Cavalier-Smith T (2006). "Rooting the tree of life by transition analyses". Biol. Direct 1 (1): 19.
^ abcGupta RS, Bhandari V and Naushad HS (2012) Molecular signatures for the PVC clade (Planctomycetes, Verrucomicrobia, Chlamydiae, and Lentisphaerae) of bacteria provide insights into their evolutionary relationships. Frontiers in evolutionary and genomic microbiology.
^ abWagner, M.; Horn, M. (2006). "The Planctomycetes, Verrucomicrobia, Chlamydiae and sister phyla comprise a superphylum with biotechnological and medical relevance". Current Opinion in Biotechnology 17 (3): 241–249.