Ellen Thro Related books Genetic Engineering: Shaping the Material of Life (Facts on File Science Sourcebooks) Facts on File • 1993 Robotics: The Marriage of Computers and Machines (Facts on File Science Sourcebooks) Facts on File • 1993 Twentieth-Century Women Politicians (American Profiles) Facts on File • 1998 Volcanoes of the United States (Venture Book) Scholastic Library Pub • 1992