The phrase "a group of external" is correct and usable in written English.
It can be used when referring to a collection of individuals or entities that are outside a particular organization or system.
Example: "The project will benefit from the insights provided by a group of external consultants."
Alternatives: "a team of outside" or "an assembly of external".
Form a group of external experts to review all US government intelligence and communications technologies.
One peculiarity of marine hulls is that they wear when exposed to a group of external factors with periodic load fluctuations.
The system along with the control law is simulated, where the system is subjected to a disturbance that emulates the action of a group of external unknown bounded forces over the links of the bipedal robot.
PGF, IB, SF, GJ and OL have together with a group of external doctors read, evaluated and scored the transcribed interviews.
The IDG is formed by a group of external multidisciplinary experts who provide evidence-based recommendations on the content, layout and development process of the index.
The practical procedure for implementing statistical equating for the Part 1 examination, was developed in conjunction with a group of external psychometricians with previous expertise at IRT and statistical equating, and used the specialist IRT software Winsteps.
The commission has assembled a group of five external reviewers and five "peers"—senior government officials involved in research policy in their own country.
The consultation successfully convened a group of prominent external advisors, alongside regional, country and headquarters staff.
Pancreatitis or pancreatic cancers are being adjudicated by a group of independent external experts.
An ethical review fulfilling the function of an IRB Institutional Review Boardd) was therefore conducted, and the study design and conduct was reviewed by a group of 16 external experts from various countries in Asia.
In early 2009, the World Health Organization convened a working group of external experts focused on tailoring sepsis management to address the challenges relevant to LMICs.
