Quotation - online puzzles

A quotation is the repetition of one expression as part of another one, particularly when the quoted expression is well-known or explicitly attributed by citation to its original source, and it is indicated by (punctuated with) quotation marks.

A quotation can also refer to the repeated use of units of any other form of expression, especially parts of artistic works: elements of a painting, scenes from a movie or sections from a musical composition.