The phrase "a concrete indication" is correct and usable in written English.
It can be used when referring to a specific and clear sign or piece of evidence that supports a conclusion or observation.
Example: "The data provided a concrete indication of the project's success, leading to further investment."
Alternatives: "a clear sign" or "a definitive signal".
"This violation is a concrete indication of Russia's acts aiming to escalate problems, despite the clear warning by our country and by Nato," Turkey's foreign ministry said.
"It's a concrete indication of a real commitment on the part of the administration," said Dana Gunders, staff scientist at advocacy group Natural Resources Defense Council and author of the Waste-Free Kitchen Handbook: "The goal is very aggressive – it could have been 10% or 30%, so they really went all the way by committing to halving the amount of food waste produced".
This can be a concrete indication of a good reputation.
"This positive operating result in the first quarter is a concrete indication to our customers, dealers and suppliers that the 2010 targets we have set for ourselves are achievable," said Marchionne.
Turkey strongly condemned the incident as a concrete indication of escalating hostilities between the two nations.
'We don't have a concrete indication that there will be an attack today or tomorrow at a specific location.'.
Unable to reach the crew, the intruders then left after an estimated 50 minutes without taking anyone or anything, and without giving any concrete indication of why they had come.
Bernd Pulverer, chief editor of The EMBO Journal, which published3 an article by Kaidi and others in 2010, says that neither the university nor his journal saw any "concrete indication" that the paper had any issues.
"Ireland is arguably the country in the world most scarred by abuse, and if he comes here and doesn't offer any concrete indication of how accountability will be delivered at long last, I think there will be an eruption.
Although Mrs. Whitman has not given any concrete indication of her plans beyond the consulting business, she has the built-in advantage of statewide name recognition and a popularity, at least in New Jersey, that has more or less held steady through her worst travails.
"It is a very concrete indication of Lower Manhattan's growing strength as a retail center, particularly the Broadway corridor".
