Gray's Anatomy is a reference book of human anatomy written by Henry Gray and illustrated by Henry Vandyke Carter, published in London in 1858.It has gone through multiple revised editions and the current edition, the 42nd (October 2020), remains a standard reference, often considered "the doctors' bible".
The 20th (twentieth) century began on January 1, 1901 (), and ended on December 31, 2000 (). The 20th century was dominated by significant events that defined the modern era: Spanish flu pandemic, World War I and World War II, nuclear weapons, nuclear power and space exploration, nationalism and decolonization, technological advances, and the Cold War and post-Cold War conflicts.
The 21st (twenty-first) century is the current century in the Anno Domini era or Common Era, under the Gregorian calendar. It began on January 1, 2001 ( MMI ) and will end on December 31, 2100 ( MMC ).