Hillier R, Edwards D, Morrissey LB (2008). „Sedimentological evidence for rooting structures in the Early Devonian Anglo–Welsh Basin (UK), with speculation on their producers”. Palaeogeography, Palaeoclimatology, Palaeoecology. 270 (3–4): 366—380. Bibcode:2008PPP...270..366H. doi:10.1016/j.palaeo.2008.01.038.
harvard.edu
adsabs.harvard.edu
Hillier R, Edwards D, Morrissey LB (2008). „Sedimentological evidence for rooting structures in the Early Devonian Anglo–Welsh Basin (UK), with speculation on their producers”. Palaeogeography, Palaeoclimatology, Palaeoecology. 270 (3–4): 366—380. Bibcode:2008PPP...270..366H. doi:10.1016/j.palaeo.2008.01.038.
uoregon.edu
blogs.uoregon.edu
Retallack GJ (1986). „The fossil record of soils”(PDF). Ур.: Wright VP. Paleosols: their Recognition and Interpretation. Oxford: Blackwell. стр. 1—57. Архивирано(PDF) из оригинала 2017-01-07. г.
web.archive.org
Retallack GJ (1986). „The fossil record of soils”(PDF). Ур.: Wright VP. Paleosols: their Recognition and Interpretation. Oxford: Blackwell. стр. 1—57. Архивирано(PDF) из оригинала 2017-01-07. г.