"existing research shows" is a correct and usable phrase in written English.
You could use it to introduce a fact or opinion that has been discussed previously, such as in this example sentence: "Existing research shows that human behavior is largely driven by underlying biological factors."
Existing research shows that these local protests did sway members of Congress at the time.
Existing research shows that both types of congregations empower their members to succeed in the modern economy and that Pentecostal churches often provide basic welfare services to their members (Trinitapoli & Weinreb 2012).
Existing research shows that people tend to escalate when prior expenditures (e.g., sunk costs) are high, whereas other research suggests that people tend to escalate when a project nears completion, regardless of prior expenditures.
Existing research shows huge variation in how individuals experience living with a new stoma but little is known of the individual experience of contemporary health care from the patient perspective.
Existing research shows that many factors should be taken into account to achieve good speech privacy in open-plan offices and improving only one of these factors may result in little improvement, so it is important to distinguish contributions of different acoustic transmission paths of open ceiling meeting rooms in open-plan offices.
Existing research shows that the main reason for Chinese couples to live apart is their jobs.
Drawing from existing research showing that sound is an important part of the sense of taste, Felipe Carvalho of Vrije Universiteit Brussel set out to see just how much various pitches interact with beers.
Professor Autor's own explanation builds on existing research showing that income inequality has soared, stretching the gap between rich and poor, and that a smaller share of Americans are making the climb.
Of course, there's a large body of existing research showing that women tend to be more communal and collaborative in the workplace and can be penalized if they aren't, since it runs counter to what's expected of them.
His findings show that these expansions are associated with recipient pre-tax earnings growth of roughly 3 4percentt, primarily among single mothers results that complement existing research showing that the EITC has a positive effect on labor market outcomes and household well-being.
A 2015 survey of studies asserted that existing research showed no support for the claim that private enterprises perform better than public ones.
