Mary Pope Osborne;Natalie Pope Boyce

• Magic Tree House Fact Tracker #32: Sharks and Other Predators: A Nonfiction Companion to Magic Tree House #53: Shadow of the Shark (A Stepping Stone Book(TM)) by Mary Pope Osborne (2015-06-23)
• Ninjas and Samurai: A Nonfiction Companion to Magic Tree House #5: Night of the Ninjas (Magic Tree House (R) Fact Tracker) by Mary Pope Osborne (2014-09-23)