The phrase "attested by their" is correct and usable in written English.
It can be used when referring to something that has been confirmed or verified by a particular group or individuals.
Example: "The findings of the research were attested by their peers, ensuring the credibility of the results."
Alternatives: "verified by their" or "confirmed by their".
The presence of the Etruscan people in Etruria is attested by their own inscriptions, dated about 700 bce; it is widely believed, however, that the Etruscans were present in Italy before this time and that the prehistoric Iron Age culture called "Villanovan" (9th 8th century bce) is actually an early phase of Etruscan civilization.
"This is attested by their activities, the way they approached the Imprint 93, and what they did later with actions and performative projects.
Certainly some of them spent some time working in the papal curia, which is attested by their subscriptions on the papal bulls.
Of the 20 Aksumite Kings attested by their coins, inscriptions corroborate the existence of only two, who happen to be the most famous kings: Ezana and Kaleb, both of whose reigns were periods of exceptional prosperity during the height of the Aksumite kingdom.
The symbolic significance of foxes is also attested by their frequent occurrence as motifs on the T-shaped pillars and elsewhere at Göbleki Tepe [35].
The HC group consisted of 13 healthy individuals who had no history of neurological disease, head injury or alcohol abuse, and displayed no signs of dementia, as attested by their scores on the Mattis Dementia Rating Scale (MDRS) [21] (mean score = 141.2, SD = 1.9).
This is attested by inscriptions which describe their joint campaigns against their arch enemy, the Pallavas of Kanchi.
The daily devotion is attested by a rubber stamp in their small record books, which are checked at school by the teacher or at home by the inminban leader, the warden whose duty was to know everything about his or her charges in the building.
To this, in recent years, the Finn has added a "my way" approach to his racing that has made him perhaps the most popular of the current grand prix drivers with fans around the world, their numbers attested by the profusion of fluttering blue-and-white Finnish flags in the grandstands and hand-lettered banners urging him to victory.
Detailed codification of types of karma and their effects were attested by Umasvati who is regarded by both Digambara and Svetambara as one of theirs.
Speaking of relations as modes allows us to acknowledge their reality, as attested by experience, without hypostasizing them.
