The phrase "add further proof" is correct and usable in written English.
It can be used when you want to provide additional evidence or support for a claim or argument.
Example: "The study's findings were compelling, and the subsequent research will add further proof to the initial conclusions."
Alternatives: "provide additional evidence" or "offer more support".
In this paper we add further proof.
"We believe the radio asset sales add further proof that CBS stock is inexpensive," Miller said.
Two new studies released this week add further proof that Americans need to break the meat habit.
For those, like me, who work as an LGBTQ activist and advocate among conservative Christians communities, these numbers only add further proof to a reality that I have been seeing among Christians for the past few years.
To add further proof to our assumption that CaMKII plays a major role in D-ribose-induced Tau phosphorylation, we inhibited the activation of CaMKII using a specific inhibitor CK59 (Konstantopoulos et al., 2007) and tested for suppression of Tau phosphorylation.
For good measure, it was discovered that powdered bismuth, an unusual pigment favoured by Raphael, had been used in the Alnwick painting, adding further proof of its authenticity.
Financially, perhaps, not everything looks so positive for Ralph Lauren, but Wednesday's show adds further proof that things might be looking up for the brand on the eve of its 50th anniversary.
Against the Eagles, Reese watched his Titans misplay a punt and fail to recover an onside kick, adding further proof to the theory that shaky special teams units give opponents shorter fields to work with, leading to more scoring.
The recent allegations follow CNN's report of a congressional "creep list" that women who work on the Hill have compiled of men who are known for inappropriate sexual behavior, adding further proof that becoming a top lawmaker seems like a sexual predator's dream job.
The Canadian team took what Rocksteady had carved out and ensured it didn't drop the ball, 2013's Arkham Origins not only adding further proof of how beautiful Arkham City is, but also how much mileage it's possible to get out of this world.
In consequence, several research groups have resorted to the deliberate addition of a soluble source of fluoride ion under stoichiometric conditions to stabilise the equilibrium between the carbene intermediate and the desired reagent, thus adding further indirect proof of the mechanistic difficulties [ 34, 35].
