"well attested by" is correct and usable in written English.
You can use it to express that something is supported or backed up by evidence. For example, "The argument was well attested by scientific data."
Neandertal occupation of Eemian environments in Europe is well attested by several archaeological sites dating to this interglacial period.
After Ibn al-Ḥâjj's death in 1114, the Almoravid Sultan appointed his brother-in-law Abû Bakr ‛Alî ibn Ibrâhîm aṣ-Ṣahrawî, known as Ibn Tîfilwît, as the governor of the province.[1] The connection of Avempace to Ibn Tîfilwît is well attested by both Ibn Ḥaqân and Ibn al-Khaṭîb.
Amenemhat IV is well attested by contemporary artefacts, including a number of scarab- and cylinder-seals.
The coregency is well attested by numerous monuments and artefacts where the names of the two kings parallel each other.
Of course, the larger the shark, the more formidable the attack, but several small specimens can be hazardous as well, a fact well attested to by seasonal attacks off the southeastern coast of the United States.
Thinis is, as yet, undiscovered but well attested to by ancient writers, including the classical historian Manetho, who cites it as the centre of the Thinite Confederacy, a tribal confederation whose leader, Menes (or Narmer), united Egypt and was its first pharaoh.
He still seethes with indignation at the CIA's failure to share information with the FBI that might have prevented the attacks on the Twin Towers: a failure which is by now well attested but which Mr Soufan chronicles in painful and angry detail.A third aim is to argue the case against torture.
Additional alteration of the painting is well attested in parish accounts; the painting was "varnished and somewhat restored" by the painter Aline Bernard (1841 1910) in 1885, and a second time in 1907 by a Nils Janzon.
The Danube Fleet (Classis Histrica) with its attendant legionary flotillas is still well attested in the Notitia Dignitatum, and its increased activity is commented upon by Vegetius (De Re Militari, IV.46).
Other arts and crafts were well attested.
Such automatic pitch lowering is well attested outside Chadic both within and outside Africa.
