How many books Laura Hillenbrand wrote?

Laura Hillenbrand has written:

'Seabiscuit.' -- subject(s): Accessible book

'Unbroken' -- subject(s): Prisoners of war, Campaigns, American Aerial operations, World War, 1939-1945, Long-distance runners, United States, United States. Army Air Forces. Heavy Bombardment Group, 307th, Biography, Japanese Prisoners and prisons

'Seabiscuit' -- subject(s): Seabiscuit (Race horse), Race horses, Horse racing, Biography

'Unbroken'

'Seabiscuit (Historias)'