本事 (běn shi): исходный материал

The director said the film was adapted from a true history book; that book was the source material for his creation.

To write this paper, she spent a lot of time collecting source materials, including old newspapers, diaries, and interview records.

Before starting to write, the screenwriter carefully read all the relevant source materials to ensure the story was historically accurate.

The source material for this documentary came from the memoirs of an old Red Army soldier; the director made only minor artistic additions.

The professor asked students to list all the source materials used in their papers and to cite the sources in an appendix.