The waves are the "First Wave", or "White Wave", which left during the Russian Revolution of 1917 and then the Russian Civil War; the "Second Wave", which emigrated during and after World War II; and the "Third Wave", which emigrated in the 1950s, 1960s, 1970s, and 1980s.
The waves of emigration are categorized as the "First Wave" (or "White Wave"), departing during the Russian Revolution of 1917 and then the Russian Civil War; the "Second Wave", which emigrated during and after World War II; and the "Third Wave", leaving in the 1950s, 1960s, 1970s, and 1980s.