1957 Documentary Film, Soviet Union, Artisty tsirka released in USA as
Circus Stars.  Leonid Kristi - Director  Availability on DVD or VHS?

manchu,

At least one other Researcher besides me has looked at this question.
I could find only references to the movie as showing jugglers, and
sites selling its movie posters. It doesn't mean it's not out there.
There may be sites selling vintage movies whose inventory lists have
not been accessed by Google.

You can try the search listings for ["vintage movies" order] to see
websites selling vintage movies (there are more than 5,000!):
://www.google.com/search?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=%22vintage+movies%22+order&btnG=Google+Search

Regards,

aceresearcher

I saw the film in early 1960 at the San Francisco Fox Theatre on a
bill with a film titled "Heller in Pink Tights".  If memory serves me
correctly, it was released through Paramount Pictures.  It contained a
full program of the Moscow Circus including Oleg Popov, Vladimir
Durov, Valentin Filatov and others.  Some of the artistes are still
working, many of the rest have retired or passed on. At the time I was
a young circus and stage performer serving in the USN.  I had often
heard of the art of the Russian Circus, but this was the first time I
actually saw it, and it changed the course of my performing career
profoundly.  I hope you can get a lead on a tape or DVD copy.         
      George Rowe

Just to fill in details on the movie:

http://us.imdb.com/Title?0193728

Artisty tsirka (1957)
 
Directed by Leonid Kristi
Writing credits Leonid Kristi
Cinematography by Ilya Gutman and Viktor Rusanov

Genre: Documentary

Credited cast:
Oleg Popov .... Himself
Vladimir Durov .... Himself
Alexandre Serge .... Himself
Vladimir Doveyko .... Himself
Margarita Nazarova .... Herself
Constantinovsky .... Himself
Rabadan Abarkoroff .... Himself
Boris Mazilhi .... Himself
Natasha Mazilhi .... Herself
Polifronov .... Himself
Lavazinski .... Himself
Valentin Filatov .... Himself

Also Known As:
Circus Stars (1957) (USA)
Runtime: USA:61 min
Country: Soviet Union
Language: Russian
Color: Color (Sovcolor)
Sound Mix: Mono
Certification: Finland:S