The phrase "a third mentioned" is not correct in standard written English.
It may be intended to refer to a third item or point that has been mentioned, but it lacks clarity and proper structure.
Example: "In the report, a third mentioned was the need for improved communication strategies."
Alternatives: "a third point raised" or "a third item noted".
Moreover, less than a third mentioned the adverse effects--like nausea, hair loss, immune suppression, and fatigue--that these treatments can cause.
(Yet, a surprising number downplayed their accomplishments beyond their financial contribution; only about 1 in 10 mentioned being a role model for her children while a third mentioned her partner as the more positive influence).
One in five reports mentioned an ethics committee (34/177), and a third mentioned consent (61/177).
HIV/AIDS as a problem in Albania: In response to questions concerning the main health problems facing Albania today, approximately a third mentioned AIDS; most were under the age of 30 and 70% lived in urban districts.
When voters, most of whom don't pay close attention to politics, are asked to choose from a long list of names, a third mention the one that they've heard in the news most recently or most frequently.
For his part in the campaign, Berryman received a third Mention in Despatches.
For his service in the final campaigns, Blamey recommended Sturdee for a knighthood, but this was reduced to a third mention in despatches.
He received a third mention in despatches posthumously, and in 2011 came under formal consideration for the award of the Victoria Cross (VC) for his performance as Perth's captain.
But a second mention was met with silence.
Yes, a second mention for the City of Angels, but it figures that Hollywood studios would exploit their own back yard.
Instead of his usual preference for pragmatic language, Geraghty smiles and gushes helplessly at a first mention of the two best horses at this week's Cheltenham Festival.
