The phrase "are indeed necessary" is correct and usable in written English.
You can use it to emphasize the importance or essential nature of something in a statement or argument.
Example: "In order to achieve our goals, certain resources are indeed necessary for success."
Alternatives: "are truly essential" or "are certainly required".
The emergency rations now being shipped, flown and trucked into the Sahel are indeed necessary and urgent by the time hunger and destitution are acute and widespread.
In this regard, the design of more efficient techniques are indeed necessary.
Implications of these results are that indirect effects from non-adjacent network relationships are indeed necessary considerations for ecosystem design and management and they can be quantified using ecological network analysis.
Other studies that address AO systems larger than the ones used in the preliminary evaluation, as well as larger samples, are indeed necessary, though not available for the time being.
Although the lower bound of the grain size is poorly determined from the extinction curve (Weingartner and Draine, 2001), we assume that amin = 0.3 nm, since a large number of very small grains are indeed necessary to explain the mid-infrared excess of the dust emission in the Milky Way (Draine and Li, 2001).
Emergency measures are indeed necessary at present, but they must remain emergency measures.
A reassessment of caesarian rates was indeed necessary.
But still, we must take this hard look in order to see if reform is indeed necessary.
He was willing to give a little ground, and admit that government action was indeed necessary to prevent depressions.
"Unfortunately, the intelligence community has not yet made a convincing argument that a separate, secret program is indeed necessary," he said.
The placental barrier, however, does allow molecules of various substances to pass through; such differential permeability is indeed necessary if the embryo is to obtain nourishment.
