Encyclopædia Britannica it is scarcely used, and reviewers have recommended that it be dropped from the encyclopaedia. The also has color transparencies of human anatomy and several appendices listing the staff members, advisors, and contributors to all three parts of the Britannica. Taken together, the and comprise roughly 40 million words and 24,000 images. The two-volume index has 2,350 pages, listing the 228,274 topics covered in the "Britannica", together with 474,675 subentries under those topics. The "Britannica" generally prefers British spelling over American; for example, it uses "colour" (not "color"), "centre" (not "center"), and "encyclopaedia" (not "encyclopedia"). However, there are exceptions to
Encyclopædia Britannica June 7, 2018, Britannica released a Google Chrome extension, Britannica Insights, which shows snippets of information from Britannica Online in a sidebar for Google search results. The Britannica sidebar does not replace Google's sidebar and is instead placed above Google's sidebar. The 2007 print version of the "Britannica" has 4,411 contributors, many eminent in their fields, such as Nobel laureate economist Milton Friedman, astronomer Carl Sagan, and surgeon Michael DeBakey. Roughly a quarter of the contributors are deceased, some as long ago as 1947 (Alfred North Whitehead), while another quarter are retired or emeritus. Most (approximately 98%) contribute to only