Further electronic searches suggest that the term became increasingly more common in the 1960s and always used in a derisive or humorous way. The "Chicago Tribune" in 1960 carried a front-page story on the speculations of a Harvard anthropologist about how aliens might look and alien sex. The article opens with the comment, "If there really are 'little green men' out there in space, there are probably also little green women–and sex." A cartoon was attached showing two amorous centaur-like male and female aliens with antennae sticking out of their heads. The article also enigmatically states, "The 'little green men' designation came from Dr. Otto Struve, director of the national radio astronomy observatory, Green Bank, W. Va. He said that's what the possible outerspacers are called 'among themselves'."