Found+by+Haddix

In which book do the main characters travel in time back to the fifteenth century? In which book does a boy find out that he is adopted as a result of a mysterious letter? In which book does a boy and his friend break into a safe to find his birth certificate? In which book did a main character use a cellphone to photograph valuable information from a file? In which book were the main characters helped by a janitor who seemed to appear and disappear magically? In which book do the main characters escape from a kidnapper by climbing through a window of the library? In which book did children try to find their "birth parents"? In which book did a list from the FBI become an important clue? In which book did one of the main characters study physics to try and solve a mystery from the past? In which book did the characters use a gadget called an Elucidator? In which book did a boy and his friends find out they are from the past?