"twofold reason" is a correct and usable phrase in written English.
It means having two reasons or aspects. You can use it in a sentence when you want to emphasize that there are two motivations or justifications for something. Example: "There is a twofold reason for implementing this new policy - to improve efficiency and to ensure fairness for all employees."
He came to criticize nationalism for a twofold reason: in Europe it had led to destructive racism and imperialism, and in India it was not founded on an adequate degree of common purpose.
Needless to say, the tourist image of Morocco takes a hit, starting with Tangier, Kilani's birthplace, a buffered city, for a twofold reason: it is the first contact point for car-bound travelers and the point of no return for migrants trying to cross the Mediterranean.
The launching of a new, highly visible and accessible peer reviewed journal on German and European Studies with a strong Asian perspective provides a twofold reason to celebrate: Not only does this journal constitute a promising and unique new platform for comparative and mutually inspiring scholarship on contemporary Germany, Europe and beyond.
The twofold reason: If the current wing were to break, the boat would be useless, and there wouldn't be time to build another for a September defense.
Whereas it is clear that AChE inhibition is not the most sensitive endpoint, the spectrum of effects reported in vitro, in animal models and in humans coherently supports that endocrine effects, especially in susceptible time windows, should deserve more attention in the risk assessment of OP insecticides for a twofold reason.
Twofold reason suggests ruling out the effect of the extent of conversion on biocatalyst deactivation within the operation time investigated (about 160 h): (a) the same deactivation extent has been measured even though different conversions have been measured; (b) constant conversion was observed under steady state conditions for long time.
