Online dictionaries and encyclopedias are normally cited in the notes rather than in bibliographies.
1 Encyclopedia Online, "Reference Entry," by Author First Author Last, Last Updated date. URL or DOI.
1 Grove Music Online, "Ellington, Duke [Edward Kennedy]," by Marcello Piras, October 16, 2013, https://doi.org/10.1093/gmo/9781561592630.article.A2249397.
For reference works, specifically substantial, authored entries, it is more appropriate to cite individual entries by author, like below. In this case, you will include these sources in the bibliography.
Author Last Name, Author First Name. "Title of Article." In Encyclopedia Title, edited by First Last (if applicable). Publisher, date. Accessed or Updated date. URL or DOI.
Hischak, Thomas. "Corgliano, John." In The Encyclopedia of Film Composers. Rowman & Littlefield Publishers, 2015. https://ebookcentral.proquest.com/lib/roosevelt/reader.action?docID=2032766&ppg=5.1. Author Name, "Title of Article," In Title of Encyclopedia, editor, Publisher, date published, doi or url.
1 Thomas Hischak, "John Corgliano," in The Encyclopedia of Film Composers, Rowman & Littlefield Publishers, Published April 16, 2015, https://ebookcentral.proquest.com/lib/roosevelt/reader.action?docID=2032766&ppg=5.
Well-known reference works, such as major dictionaries and encyclopedias, are normally cited in notes rather than in bibliographies. Remember that if it is the first edition or only one volume, you don't have to cite it. If a physical edition is cited do the following:
1 Title, #th ed. (Year), under "Title of reference entry."
1 The Chicago Manual of Style, 18th ed. (2024), under "Reference works consulted in physical formats."
Other reference works will be listed with full publication details like other book resources.
Title. #th ed. # vols. Publisher, Year.
Encyclopedia of heavy metal music. Greenwood Press, 2009.
1 Encyclopedia Name, #th ed. (Year), under "Name of entry."
1 Encyclopedia of Heavy Metal Music, (2009), under "Cacophony."