The phrase 'a influential factor' is correct and usable in written English.
You can use it to describe something that has a strong and lasting effect on a situation. For example: "Price was an influential factor in deciding which car to buy."
Moreover, the probability distribution of the mean shift δ is studied explicitly as an influential factor in a factorial experiment.
England lost at the Waca, but Collingwood's catch — a wonderful, springing effort at third slip — ensured that Ricky Ponting would find no release from a tortuous run of form, an influential factor in England's dominance.
However, all reported studies used a noncompartmental approach with a low statistical power for detecting concomitant food intake as an influential factor on piperaquine pharmacokinetics, compared to a modeling approach.
Only four women in our sample were under the age of 35, the group where fertility concerns are an important issue, and could be an influential factor in decisions regarding preventive therapy for breast cancer.
Other studies have reported the perceived expectations of the breast surgeon to be an influential factor, especially among women with a preference for BCS [ 14].
The two are still well down in the single digits in most national polls, but in states where Gov. George W. Bush and Vice President Al Gore are in a tight race, like Illinois, they could be an influential factor.
Aging correlates with a progressive impairment of mitochondrial homeostasis and is an influential factor for several forms of neurodegeneration.
On a socio-demographic level, respondents' age was observed as an influential factor in these subjective evaluations.
Regulated orientation of the spindle has been shown to be an influential factor in cell fate decisions during development of a variety of systems.
The amino acid sequence of the prion protein (PrP) is known to be an influential factor for cross-species transmission of TSE disease to a new host.
(5) Time is an influential factor as well.
