'which yet needs' is correct and usable in written English.
You can use this phrase when referring to something that still requires additional effort or attention to be completed. For example: "The project is nearly finished, which yet needs the approval of the board of directors."
Most of them supported classical results and named novel regions, which yet need to be validated in independent studies.
It was hard, however, to ignore the tensions that emerged between the two countries before the deal, which were only compounded by German mistrust on hearing that French advisers helped draft the Greek paper and the underlying suspicion that Paris only resisted a Grexit because it too faces some challenging structural reforms with which it might yet need considerable German help.
Suharto's real talent lay in manipulating the military elite on which he relied and yet needed to divide and rule.
The fact that it's not a normal market has led every other advanced economy to at least partially take this function out of the market, to avoid the "externalities" that arise when people forego coverage yet need care (which turns out to be a much bigger problem for society then if people forego the broccoli course).
Points that yet need refining, with which you may be able to help: How does the young Blairite uncover McBride's secrets?
Ford, which lost $8.7 billion through September, may yet need taxpayer money.
Cumberbatch was adding a rare white voice in support of the growing number of black actors who are trying to encourage change in a sector which sorely needs it, yet seems incapable of achieving it without relentless pressure and coercion.
As creations of the UN Security Council, they also have undisputed legal authority something which may yet be needed in Iraq.
