What is the fine-grained topic of the following text: During this decade he produced such iconic series as the abstract Oxidation paintings, which combined urine on metallic copper; the classic Ladies and Gentlemen portraits depicting New York’s drag community; his screen prints of the actor and Native American political activist Russell Means, and of the Chinese Communist leader, Mao Zedong; as well as the Shadow, Skulls and Hammer & Sickle series. Only return the topic.
The artist's iconic series and works during a specific decade.