The phrase "are an appropriate source" is correct and usable in written English.
You can use it when discussing the suitability or relevance of a source of information or material in a specific context.
Example: "The articles published in peer-reviewed journals are an appropriate source for academic research."
Alternatives: "are a suitable source" or "are a valid source".
Parents and youths may not be aware that GPs are an appropriate source of care for mental health problems [ 25].
Thus, metagenomes are an appropriate source for estimation of the riboswitch abundance in microbial communities and the diversity of their functions.
Administrative health data are an appropriate source to conduct long-term follow-up studies, but validation studies are important to ensure that true cases of disease can be ascertained in these data.
Firstly, mental health literacy programmes may help to increase young people's and their parents' recognition of mental health problems and raise their awareness that GPs are an appropriate source of care for such problems [ 55, 56].
SF is an appropriate source of MSCs because of its direct application on OA.
Another thorny question, particular to PlayPump, is whether children playing is an appropriate source of energy for water.
"We were gratified that voters saw us as important, and that they felt this was an appropriate source of funding," said Dr. Nancy McCallin, president of the Colorado Community College System.
"I thought the idea of beautiful, alluring but ultimately powerful and dangerous things was an appropriate source of inspiration for women fighting breast cancer," she said.
"The resolution proved that the United Nations Security Council cannot be an appropriate source to protect people's rights and security," the statement said.
The experimental data will practically be an appropriate source of information for environmental engineers to design a natural treatment scenario for saline wastewater treatment.
It is clear that the DWP does not consider housing benefit to be an appropriate source of funding for emergency night shelters (indeed, it supported the legal appeal by Anglesey council that led to the current ruling) though it will not say explicitly.
