Given the question: Information:  - Literature, in its broadest sense, is any single body of written works. More restrictively, it is writing considered as an art form, or any single writing deemed to have artistic or intellectual value, often due to deploying language in ways that differ from ordinary usage. Its Latin root "literatura"/"litteratura" (derived itself from "littera": "letter" or "handwriting") was used to refer to all written accounts, though contemporary definitions extend the term to include texts that are spoken or sung (oral literature). Literature can be classified according to whether it is fiction or non-fiction and whether it is poetry or prose; it can be further distinguished according to major forms such as the novel, short story or drama; and works are often categorized according to historical periods or their adherence to certain aesthetic features or expectations (genre).  - Sonata (Italian: , pl. "sonate"; from Latin and Italian: "sonare", "to sound"), in music, literally means a piece "played" as opposed to a cantata (Latin and Italian "cantare", "to sing"), a piece "sung". The term evolved through the history of music, designating a variety of forms until the Classical era, when it took on increasing importance, and is vague. By the early 19th century, it came to represent a principle of composing large-scale works. It was applied to most instrumental genres and regardedalongside the fugueas one of two fundamental methods of organizing, interpreting and analyzing concert music. Though the musical style of sonatas has changed since the Classical era, most 20th- and 21st-century sonatas still maintain the same structure.  - A Scots Quair is a trilogy by the Scottish writer Lewis Grassic Gibbon , describing the life of Chris Guthrie , a woman from the north east of Scotland during the early 20th century . It consists of three novels : Sunset Song ( 1932 ) , Cloud Howe ( 1933 ) , and Grey Granite ( 1934 ) . The first is widely regarded as an important classic ( voted Scotland 's favourite book in a 2005 poll supported by the Scottish Book Trust and other organisations ) but opinions are more varied about the other two .  - A trilogy (from Greek - "", "three" and - "-logia", "discourse") is a set of three works of art that are connected, and that can be seen either as a single work or as three individual works. They are commonly found in literature, film, or video games. Three-part works that are considered components of a larger work also exist, such as the triptych or the three-movement sonata, but they are not commonly referred to with the term "trilogy."  - Lewis Grassic Gibbon was the pseudonym of James Leslie Mitchell (13 February 1901  7 February 1935), a Scottish writer.    Given the paragraphs above, decide what entity has the relation 'author' with 'james leslie mitchell'.
The answer is:
a scots quair