The phrase "a poor source" is correct and usable in written English.
It can be used to describe a reference or origin of information that is not reliable or credible.
Example: "The article was based on a poor source, which led to several inaccuracies in the report."
Alternatives: "an unreliable source" or "a questionable source".
As a result, Dr. Rhyne said, the system is a poor source of data on the trade of biodiverse wildlife.
Mario A PC is a poor source for hi-fi, but that probably doesn't matter if you mainly want to change the sound to suit your ears.
For part of the year, when the sun barely clears Iceland's horizon, sunlight is a poor source of vitamin D — but the vitamin is plentiful in fish oils.
If a man suddenly finds himself thrown together with a woman he barely knows and may not even like, if her rising expectations in the wake of the birth leaves her feeling it's impossible to please her, and if he believes she views him as expendable if a better catch comes along, she will be seen as a poor source of commitment.
But an analysis of the nitrogen isotopes in the bone collagen, which indicates the main source of protein in one's diet, suggests they were fed breast milk — a poor source of vitamin D — until they were 2. And assuming the Medicis followed the custom of the time, they would have supplemented the breast milk only with soft bread and apples, which do not contain much of the nutrient.
Together, the systemic risks and non-competitive cost nature of fossil fuels are making them a poor source of risk-adjusted returns.
The cassava root is a relatively poor source of minerals and vitamins, however, there is a high content of calcium and phosphorus in the storage roots.
Regardless of whether you believe porn is moral or immoral, it is without a doubt a poor source of information for how to have real sex with a real, live person.
Breast milk is a relatively poor source of vitamin D; therefore, in order to maintain an optimal vitamin D status during early infancy, it is essential for the mother to have an adequate vitamin D status during pregnancy [ 11].
One explanation is that so-called experts turn out to be, in many situations, a stunningly poor source of expertise.
(IMDb is a notoriously poor source for casting information, however, and the official press release declines to mention those actors).
