writers in film and three teams of writers in television, may receive credit for a production. The Writers Guild has the right to protest any company's proposed credits, regardless of whether the writers do. To determine credits, "it is vital that the writer keep copies of all work done", and submit copies to the Writers Guild promptly upon completion. Scripts as well as substantial story ideas and other literary material are counted for credit decisions. When there is more than one participant writer on a production, "all participants have the right to agree unanimously among themselves as to which of them shall receive writing credits on the screen and in what form", as long as the agreed form meets requirements. The MBA also establishes that the agreed form "shall not be suggested or directed by the [production] Company". The Writers Guild also officially presumes that any writer has access to all prior material written for the project during their employment, underscoring credits given to prior writers who have been removed from projects. Materials used for research are not credited, but source material as defined by the WGA receives credits. The appropriate credit to use for source material is anything indicative of the nature and relationship of the source material and the final script, with the WGA providing the examples "From a Play by, From a Novel by, Based upon a Story by, From a series of articles by, Based upon a [teleplay/Screenplay] by". Once a writer has received both the notice of tentative credits and the final script, they can either agree with the production's tentative credits, in which case they do nothing, they can discuss the credits with the other writers through the Writers Guild, or they can challenge the tentative credits within a certain time period. If a participant writer disagrees with the credits, but there are other participants and it is seen that an agreement may be reached between them, the Screen/Television Credits Administrator must make a best attempt to arrange discussion between all writers before arbitration is sought. Credit forms Teams Credits are handled differently for individual writers and for "teams". A team of writers is defined by the WGA as "two writers who have been assigned at about the same time to the same material and who work together for approximately the same length of time on the material"; the work of the two writers