What pair of authors used themes and characters from a fairy tale published in 1812?
Snow White "Snow White" is a 19th-century German fairy tale which is today known widely across the Western world. The Brothers Grimm published it in 1812 in the first edition of their collection "Grimms' Fairy Tales". It was titled in German: Sneewittchen (in modern orthography "Schneewittchen") and numbered as Tale 53. The name "Sneewittchen" was Low German and in the first version it was translated with "Schneeweißchen". The Grimms completed their final revision of the story in 1854.
Brother and Sister "Brother and Sister" is a well-known European fairy tale which was, among others, written down by the Brothers Grimm in their collection of "Children's and Household Tales (Grimm's Fairy Tales)". It is alternatively known as "Little Sister and Little Brother" or (in the Grimm's version) ""Brüderchen und Schwesterchen"".