The phrase "and maintain a certain" is correct and usable in written English.
You can use it when discussing the need to keep or uphold a specific quality, standard, or condition.
Example: "To ensure the success of the project, we must adhere to the guidelines and maintain a certain level of quality throughout the process."
Alternatives: "and uphold a specific" or "and keep a particular".
States answering the call of the overlord were expected to contribute and maintain a certain number of war chariots.
"There are the top 10 violinists, who can play whatever they like and maintain a certain celebrity status – and good for them," she agrees.
If they successfully complete a program designed to prepare them for the university and maintain a certain average, they would be guaranteed a place at one of the university's campuses.
It brings pressure to deliver and maintain a certain standard of research, but also an incredible sense of pride".
Furthermore, the influence of inspections is considered in order to extend and maintain a certain target safety level.
When the de novo pathway is suppressed, the salvage pathway is upregulated to compensate for this suppression and maintain a certain level of thymidine supply [31, 32].
He promoted his job in an insidious way constantly, and maintained a certain false cheeriness at all times.
The middle movement begins in unison and maintains a certain choral quality, despite the ensuing agitated rhythms and dense harmonies.
"The Kuna are very big on protecting their image and maintaining a certain level of control over their people.
Diplomatic service is not just about service abroad, it is also about promoting the image of the country and maintaining a certain decorum in state-to-state relations.
You must carry Fogg's luggage (indeed, you must decide what to pack in it), barter with drivers, and generally work to insure that the folly keeps to schedule and maintains a certain level of comfort.
