Jules Archer was one of the most respected names in nonfiction for young people. During his lifetime he published more than seventy books, which have been translated into twelve languages throughout the world. He lived in Scotts Valley, California, until his death in 2008.

Kathleen Krull left her career as an editor in 1984 to turn to writing, most recently the Women Who Broke the Rules series. Her more than sixty books have garnered starred reviews and awards, and the Children's Book Guild of Washington, DC, honored her with its Nonfiction Award for her body of work that "has contributed significantly to the quality of nonfiction for children.? She lives in San Diego, California.