Norby and Yobo's Great AdventureIsaac Asimov, Janet Asimov
science fiction, young adult
When Jeff and his robot Norby accompany Admiral Yobo to prehistoric times so the admiral can do family research, the trip turns into a dangerous adventure.
Janet Asimov (maiden name Janet Opal Jeppson, born 1926) is an American science fiction author, psychiatrist, and a psychoanalyst.
Janet Asimov started writing children's science fiction under the name J. O. Jeppson in the 1970s. She was married to Isaac Asimov from 1973 until his death in 1992, and they collaborated on a number of science fiction books aimed at young readers, including the Norby series.
Janet Asimov. Wikipedia.