Title: Gandhi, Mao, Mandela, and Gorbachev
Subjects: World politics, Gandhi, mahatma, 1869-1948, Mao, zedong, 1893-1976, Mandela, nelson, 1918-2013, Gorbachev, mikhail sergeevich, 1931-, World politics, 20th century
People: Gandhi Mahatma (1869-1948), Mao Zedong (1893-1976), Mikhail Sergeevich Gorbachev (1931-), Nelson Mandela (1918-)
Time periods: 20th century