The phrase "a third strand of" is correct and usable in written English.
It can be used to introduce an additional element or aspect in a discussion or argument, often in contexts involving multiple components or perspectives.
Example: "In addition to the economic and social factors, a third strand of our analysis will focus on environmental impacts."
Alternatives: "an additional aspect of" or "a supplementary element of".
Egypt should be a third strand of the U.S. policy of backing moderation and reconciliation.
This provided a third strand of his past that can be seen to have had a direct bearing on his books.
And in a third strand of attack, campaigners at Warwick University said BP was continuing to resist opening its corporate archive based on the student campus.
Bringing these ideas together provides an innovative, dynamic perspective on a third strand of literature from health geography that examines hospitals as 'therapeutic landscapes'.
A third strand of the paper, a writing paper also marked internally, showed that 45 per cent got a top-grade pass.
In a third strand of the book, she returned to some of her own most troubling memories: the time her father decided to send his three daughters back to their mother midway through a visit, and rang to see if she was out with another man; the time he asked at bedtime if she had started her periods; the car journey she and Jonathan made when Jake was born, to show him to his grandfather.
Science fiction is full of robots-usurping-humans stories, sometimes entwined with a second strand of anxiety: seduction.
A second strand of opposition comes from what I think of as the Bah Humbug caucus: fiscal scolds who routinely issue sententious warnings about rising debt.
He also faces no further action over a second strand of the police investigation, into suspected conspiracy to pervert the course of justice and perjury in relation to the outing of Nightjack.
Pakistan could also leverage its presence in the peace process through its close ally Saudi Arabia, which recently offered to host a second strand of the peace talks in its capital, Riyadh.
French prosecutors are believed to be pursuing a twin-track approach: pursuing those they believe to have been involved specifically in the IAAF corruption while also considering a host of wider, related issues as part of a second strand of inquiry.
