During the 1930s and 1940s, the Nazis made Jews wear yellow ribbons or stars of David with the word ""Jude"" ("Jew") on them. Racial laws discriminated against Jews and Roma people (Gypsies). For example, Jewish doctors were not allowed to treat Aryan patients; Jewish professors were not allowed to teach Aryan students. Jews were not allowed to use any public transportation, besides the ferry; ride bicycles; or ride in cars. They were allowed to shop only from 3:00pm to 5:00pm, and only in stores owned by Jews. They could not go to theaters, swimming pools, or any other places for entertainment.