Willis Tower, formerly the Sears Tower, Chicago, the tallest building in the United States. Until the opening of the 1,483-ft (452-m) Petronas Towers (1997) in Kuala Lumpur, Malaysia, it was the world's tallest building. Constructed from 1970 to 1974 for Sears, Roebuck & Co., it rises 110 stories to a height of 1,450 ft (442 m); the 253 ft (77 m) television antenna topping it makes it the world's third largest freestanding structure at 1,703 ft (519 m). Designed by the firm of Skidmore, Owings and Merrill, the building is supported structurally by square tubes of welded steel with floors suspended within the tubes, a technological innovation that was developed specifically for the mammoth skyscraper by architectural engineer Fazlur Kahn. The tower has an exterior of black aluminum and bronze-toned glass cut by black bands. It was renamed in 2009.
"Willis Tower." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (May 21, 2019). https://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/willis-tower
"Willis Tower." The Columbia Encyclopedia, 6th ed.. . Retrieved May 21, 2019 from Encyclopedia.com: https://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/willis-tower
Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).
Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.
Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:
Modern Language Association
The Chicago Manual of Style
American Psychological Association
- Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
- In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.