The phrase "a long-term collaboration" is correct and usable in written English.
It can be used when referring to a partnership or working relationship that is intended to last for an extended period of time.
Example: "Our company is seeking a long-term collaboration with organizations that share our values and goals."
Alternatives: "an extended partnership" or "a sustained cooperation".
Groover's work with the Arboretum became a long-term collaboration.
But Damon found fame as one-half of a long-term collaboration.
Although technically, I am not "in residence"; it will be a long-term collaboration over the next few years.
In June Dr. Havasy sealed a long-term collaboration with Nassau County to make Tanglewood the center's base, a place where future problem solvers can think and learn.
This show marks the beginning of a long-term collaboration between the institution and Elton John and David Furnish, who have agreed to give works to the nation.
The Analytic Web project, a long-term collaboration between ecologists at Harvard Forest and computer scientists at UMass Amherst, is developing methods and tools to address this problem.
The experiment was conducted as part of a long term collaboration between Prof. Boashash, Director of the SPRC and Prof. Paul Colditz, Director of the Perinatal Research Centre at the University of Queensland.
Even if archaeologists had reservations about elements of the Ryan-Pitman hypothesis, Dr. Ammerman recommended that they begin a "sustained long-term collaboration" with the geologists and thus avoid "a lot of misunderstanding and tension".
In 1990 the FBI raided Jock Sturges's San Francisco studio as part of an investigation into child pornography: his work featured adolescent and pre-adolescent girls in naturist communities (all photographed with their parents' consent) as well as a famous long-term collaboration with Misty Dawn, whom he photographed from a young child until her 20s.
He enjoyed a fruitful long-term collaboration with electronics enthusiast Roger Mayer, whom he once called "the secret" of his sound.
Since that first meeting in Albania in 2002, a commitment to long-term collaboration, coupled with the emerging risk of pandemic influenza and the mandate of the revised IHR, have driven new efforts to strengthen cross-border communicable diseases control across southeastern Europe.
