John O'Brien has written at least 12 books. Their most popular book is Blockhead: The Life of Fibonacci with 2 saves with an average rating of 4⭐.
Series
93 released booksAuthored 0% of series
Who Was . . . ? Series is a 93-book series with 93 released primary works first released in 2002 with contributions by Michael Burgan, Who H.Q., and Tui T. Sutherland.