The functions of nursery rhymes in the detectives of Agatha Christie

Required
ONE chapter for the thesis, the theme of the entire work "The functions of nursery rhymes in the detectives of Agatha Christie."
- the approximate title of the chapter: Nursery rhymes and detective fiction
-the chapter should consist of 2 subparagraphs:
1.the origin and types of nursery rhymes (mainly in England)
2.Functions of nursery rhymes in detective fiction
Necessary:
- 20 pages of text in English (font 12 Times New Roman, interval 1,5)
- the chapter should be framed with all the links as in the thesis
Important:
-the wish of my supervisor- throughout the chapter, there should be a constant connection between nursery rhymes and detective stories
-I will share the sources that I found