Encyclopedias are great for:
Motif-Index of Folk LIterature (also known as Stith Thompson)
A database of elements, motifs, that occur in fairy and folk tales from all over the world. Can be challenging to use. Ask a Librarian if you get stuck at any point.
Aarne-Thompson-Uther Classification of Folk Tales
A typology of folk tales from many cultures and languages.
Literature Resource Center A basic literature database combining biographical, bibliographical, and contextual information on authors and their works (fiction, nonfiction, poetry, drama, history, and journalism)..
Folklore : an encyclopedia of beliefs, customs, tales, music, and art c1997 Olin Library Reference (Non-Circulating) Oversize GR35 .F63x 1997 +
The Oxford Companion to Fairy Tales. New York: Oxford UP, 2015.
The Cambridge Companion to Fairy Tales (2015) (Olin Library GR550 .C36 2015)
The Greenwood Encyclopedia of Folktales and Fairy Tales. 3 volumes. Westport, CT: Greenwood, 2008. (Olin Reference GR 74 .G73 2008 +)
Medieval folklore : a guide to myths, lgends, tales, beliefs, and customs Oxford ; New York : Oxford University Press, 2002. (Olin Reference GR35 .M43 2002)
Encyclopedia of Romantic Literature. General editor, Frederick Burwick. Malden, MA: Wiley-Blackwell, 2012. 3 vols. (Olin Reference PR447 E55 2012) "A three-volume reference work that covers British artistic, literary, and intellectual movements between 1780 and 1830, within the context of European, transatlantic and colonial historical and cultural interaction.
Encyclopedia of the Gothic. General editors: William Hughes, David Punter, and Andrew Smith. Malden, Mass. ; Oxford : Wiley-Blackwell, 2013. 2 vols. (Olin Reference PN3435 E56 2013+) All aspects of the Gothic. The A-Z entries provide coverage of relevant authors, national traditions, critical developments, and notable texts that continue to define, shape, and inform the genre.