* Trefousse, Hans L. ''Andrew Johnson: A Biography'' (1989) [http://www.questia.com/library/book/andrew-johnson-a-biography-by-hans-l-trefousse.jsp online edition] | * Trefousse, Hans L. ''Andrew Johnson: A Biography'' (1989) [http://www.questia.com/library/book/andrew-johnson-a-biography-by-hans-l-trefousse.jsp online edition] |