John Davies, A History of Wales, London, Penguin Books, 1994, p. 7, ISBN 0-14-014581-8.
«Another revelation of carbon-14 is that there were fairly numerous communities of agriculturalists in Britain by 4000 BC ... There is a conflict of views concerning the relationship between the Mesolithic and the Neolithic peoples. According to one interpretation, the scanty Mesolithic population was swept aside ... According to another interpretation, the relationship was highly creative, for it was in precisely those areas where the intrusive farmers met the indigenous population that architecture was born. The western extremities of Europe – Spain, Brittany, Britain and Ireland – are dotted with megalithic structures usually known as cromlechi, although it should be remembered that to the archaeologist the cromlech is only one version of such structures. It used to be assumed that the inspiration to build the cromlechi came from the Near East, but through another of the revelations of carbon-14 it has been proved that they are the first substantial, permanent constructions of man and that the earliest of them are nearly 1500 years older than the first of the pyramids of Egypt.»
