The phrase "a small firm of" is correct and usable in written English.
It can be used when referring to a business or organization that is small in size and is typically followed by a description of the type of work or services the firm provides.
Example: "She works at a small firm of architects that specializes in sustainable design."
Alternatives: "a small company of" or "a small business of".
Her first job was as a shorthand typist with a small firm of accountants, where she was paid £1 a week.
The schedule was sent by Andertons, a small firm of accountants in Catford, south-east London, who had briefly been hired by Ryan.
Although I run a small firm of eight tax professionals, the indictment of Arthur Andersen has taken its toll on us, too.
It was there that a small firm of wildcat drillers, Mitchell Energy, pioneered the application of two oilfield techniques, hydraulic fracturing ("fracing", pronounced "fracking") and horizontal drilling, to release natural gas trapped in hardy shale-rock formations.
In addition to Libeskind, there was Norman Foster; a team led by Rafael Viñoly and Frederic Schwartz; a team consisting of Richard Meier, Charles Gwathmey, Peter Eisenman, and Steven Holl; a team including Greg Lynn, Jesse Reiser, and Ben Van Berkel; Skidmore, Owings & Merrill; and Steven Peterson and Barbara Littenberg, partners in a small firm of architects and urban designers in New York.
Codassium is built by Wreally Studios, a small firm out of LA that just builds a lot of neat stuff.
The situation is ripe for a smaller firm to take advantage of".
The project comes from Shiny Heart Ventures – a small firm that consists of Frank Gruber and Jen Consalvo.
If you have a teen who can do this, I know a small firm in need of a good accountant.
Sales for Sadia in 2007 were a little more than $5 billion; so, it's still a small firm with plenty of room to grow.
To quote the founder of a small firm: "'We also make use of intermediaries (to get businesses).
