Which Tolkien book contains the story of Túrin Turambar in a standalone published form?

The Children of Húrin contains Tolkien’s story of Túrin Turambar in a standalone published form.

Christopher Tolkien edited the book from J.R.R. Tolkien’s versions, drafts, and related writings, and it was published in 2007. The narrative follows Túrin, the son of Húrin, during the First Age and traces his life through exile, warfare, tragedy, and the curse associated with Morgoth.

The story had already appeared in shorter or less complete forms. Material connected with Túrin is found in The Silmarillion and in Unfinished Tales, while earlier versions were published in Christopher Tolkien’s multi-volume histories of Middle-earth. The 2007 book presents a continuous narrative rather than only an episode within a larger mythology.

Túrin’s story is one of Tolkien’s major tragic tales, alongside the stories of Beren and Lúthien and the fall of Gondolin. Its publication does not mean J.R.R. Tolkien completed a final manuscript himself; Christopher Tolkien assembled and edited the text from his father’s papers.