Hind, R. R. (1947). Spirits unbroken: The story of three years in a civilian internment camp, under the Japanese at Baguio and at old Bilibid prison in the Philippines from December, 1941, to February, 1945. J. Howell.

Hind, Robert Renton. Spirits Unbroken: The Story of Three Years in a Civilian Internment Camp, Under the Japanese at Baguio and at Old Bilibid Prison in the Philippines from December, 1941, to February, 1945. San Francisco: J. Howell, 1947.

Hind, Robert Renton. Spirits Unbroken: The Story of Three Years in a Civilian Internment Camp, Under the Japanese at Baguio and at Old Bilibid Prison in the Philippines from December, 1941, to February, 1945. J. Howell, 1947.